# Upcoming Events

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### Pi+ Cross Section on Liquid Argon for the LArIAT Experiment by Gregory Pulliam

May 14, 2019, 1:30 PM-2:30 PM

Room 202 Physics Bldg.

LArIAT (Liquid Argon in a Testbeam) was a LArTPC experiment exposed to a charged-particle beam at the test-beam facility at Fermi National Accelerator Laboratory. This analysis measures the pi+-LAr cross section over an interacting energy range of 50-1100 MeV, accounting for background species and reconstruction effects. This is the first such measurement of this process. The result can be useful in tuning simulations for future liquid argon experiments such as DUNE and SBN.

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### Talk by Gabriele

May 3, 2019, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Judah

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### Lattice for Beyond the Standard Model Physics 2019

May 2, 2019, 9:00 AM-5:00 PM

Room: 202/204 Physics Bldg.

Host: S. Catterall (smcatter@syr.edu); Ethan Neil (ethan.neil@colorado.edu)

The focus of this workshop will be on the role that Lattice numerical simulations can play in the study of possible strong interactions in Beyond the Standard Model (BSM) physics, and in particular within the following topic areas:

• Composite dark matter
• Composite Higgs models and EWSB
• Inflation and preheating
• Other strongly coupled models, including many-fermion gauge theories and SUSY
• Theoretical applications in conformal field theory, quantum computing, and other areas

Lattice gauge theorists and continuum phenomenologists/theorists will meet and present talks in these areas, with the goal of increasing the interplay between the groups, and generating new ideas and projects.

For details and registration, please visit the event's website

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### TBA by Simone Blasi

Apr 26, 2019, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Jay Hubisz/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

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### Flow and Clogging of Granular Materials by Kerstin Nordstrom

Apr 26, 2019, 11:00 AM-12:00 PM

Room: 202/204 Physics Bldg.

Host: Prof.Joseph Paulsen/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Granular materials are commonplace and their interparticle interactions are typically simple contact forces. Yet we still have much to learn about their rich, sometimes perplexing behavior. In this talk, I will present results from high-speed video analysis and complementary simulations of granular flows. In particular, we characterize the mesoscale structure and dynamics of the system using kinematic data from >10,000 particles in the system at extremely high time and spatial resolution. I will also highlight how several of our characterization metrics can yield insight into other systems of "particles" such as migrating cells and robots.

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### What’s the matter with granular matter? by Kerstin Nordstrom

Apr 25, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof.Joseph Paulsen/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Sand, soils, powders, particles, grains... Granular materials are all around us, and yet we are still trying to understand them. In this talk, I will present some outstanding questions about granular material phenomena, what the challenges are in studying them, and visit recent attempts to address these questions. Specific phenomena addressed will include (but may not be limited to) the jamming transition, impact cratering, and animal / robotic locomotion.

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### Talk by Patrick

Apr 19, 2019, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Judah

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### Shaping nanoparticle assemblies at the interface of liquid crystals, by Lisa Tran

Apr 19, 2019, 11:00 AM-12:00 PM

202 Physics Bldg.

Host: Prof. Lisa Manning / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Liquid crystals are ubiquitous in modern society. Whenever we send a message with our cellphones, use a calculator, or check our emails, we are interacting with LCDs - liquid crystal displays. These materials are the basis of the modern display industry because of their unique properties. They can be manipulated with electric fields and can alter light. They are also deformable because they are elastic fluids. These properties allow for liquid crystals to be engineered into a pixel. Despite these advances in their technological applications, the structures that liquid crystals can form are yet to be completely understood. Current research aims to elucidate these structures to further develop liquid crystal-based technologies.

Since liquid crystal molecules tend to order with one another, they can respond to geometrical confinement. Geometrical constraints can create patterns and defects – localized, "melted" areas of disorder that can lower the distortion in the system and that can drive the assembly of objects. I will present recent work in which defects are controlled by using microfluidics to create liquid crystal double emulsion droplets – confining the liquid crystal into spherical shells. Molecular configurations are controlled by the topology and geometry of the system and by varying the concentration of surfactants. Defect structures are examined through experiments and simulations. I will then present recent experiments where nanoparticles are used in place of traditional surfactants to pattern them at the liquid crystal-water interface. This work opens up fundamental questions about the role of bulk elasticity and surface tension in interfacial assembly and has the potential to dynamically template nanomaterials for the enhancement of liquid crystal-based optical devices and sensors.

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### Breaking the Myth of the "Non-Traditional" Physicist: The Real Story About Employment for Physics Graduates by Crystal Bailey

Apr 18, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Steven Blusk, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Physics degree holders are among the most employable in the world, often doing everything from managing a research lab at a multi-million dollar corporation, to developing solutions to global problems in their own small startups. Science and Technology employers know that with a physics training, a potential hire has acquired a broad problem-solving skill set that translates to almost any environment, as well as an ability to be self-guided and -motivated so that they can teach themselves whatever is needed to be successful at achieving their goals. Therefore it's no surprise that the majority of physics graduates find employment in private--sector, industrial settings. At the same time, only about 25% of graduating PhDs will take a permanent faculty position--yet academic careers are usually the only track to which students are exposed while earning their degrees.

In this talk, I will explore less-familiar (but more common!) career paths for physics graduates, and will provide information on resources to boost your career planning and job hunting skills.

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### Gravitational Wave Detectors: present and future by Gabriele Vajente

Apr 17, 2019, 12:30 PM-2:00 PM

Room: 202/204 Physics Bldg.

Host: Stefan Ballmer. Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Three years have passed since the first detection of a gravitational wave signal from the coalescence of two binary black holes. Since then, nine more binary black holes events and one binary neutron star event have been observed. This talk will describe how we can detect gravitational waves with laser interferometers, the main sources of disturbance that limit the sensitivity of the current detectors and the plans for future upgrades.

HE

Apr 12, 2019, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Judah

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### Biophysical force regulation in cells and tissues, by Mingming Wu

Apr 12, 2019, 11:00 AM-12:00 PM

202 Physics Bldg.

Host: Prof. Alison Patteson / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Mechanical interactions between cells and their surrounding environment (other cells and/or extracellular matrices) critically regulate cell and tissue function including tumor invasion. The key regulator here is the cell generated force, which is essential for formulating or predicting cell/tissue dynamics and morphogenesis. In this talk, I will discuss our understanding of how single cells interact with three dimensional polymer network using an integrated experimental and theoretical modelling method. Our work revealed a reciprocal mechanical interaction between the cell and the polymer network, in that, cells pull and align the network, in return, the stiffened network promotes cell force generation. I will also discuss about our recent work on how cell force regulates tumor spheroid formation and dissociation in a controlled and three dimensional environment.

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### Discovering the Higgs all over again. Now with Machine Learning. by Phil Harris

Apr 11, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Matthew Rudolph. Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Standard model production of the Z (or W) boson decaying to light quarks had not been observed in a hadron collider; it was thought to be impossible. We present a new technique to observe these productions and we observe a clear W and Z peak and with the addition of Machine Learning, we apply this approach to esonances
decaying to b-quarks including, for the first time, Higgs bosons decaying to b-quarks produced through gluon fusion. From these results, we observe serious limitations in our computing and data flow model and we present a new approach to overcome these limitations through the use of a heterogenous computing model relying on FPGAs and CPUs. Finally, we look at the broader scope of accelerated computing in LHC physics and discuss how ML can lead the way to fundamental, yet to be performed, measurements at the LHC.

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### Geometric and Topological Aspects of Soft & Active Matter by Suraj Shankar by Suraj Shankar

Apr 10, 2019, 2:00 PM-3:30 PM

Room: 202/204 Physics Bldg.

Advisor: Prof. Cristina Marchetti, Prof. Mark Bowick-Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Topological and geometric ideas are now a mainstay of condensed matter physics, underlying much of our understanding of conventional materials in terms of defects and geometric frustration in ordered media, and protected edge states in topological insulators. In this talk, I will argue that such an approach successfully identifies the relevant physics in metamaterials and living matter as well, even when traditional techniques fail. The first will be the problem of kirigami mechanics, i.e., designing a pattern of holes in a thin elastic sheet to engineer a specific mechanical response. Using an electrostatic analogy, holes are shown to act as sources of geometric incompatibility, a feature that can fruitfully guide design principles for kirigami metamaterials. In the second half of the talk, I will switch to describe active matter. These are nonequilibrium systems composed of self-driven interacting units that exhibit large scale collective and emergent behaviour, as commonly seen in living systems such as a flock of birds or a bacterial suspension. By focusing on active liquid crystals in two dimensions, with both polar and nematic orientational order, I will show how broken time-reversal symmetry due to the active drive allows polar flocks on a curved surface to support topologically protected sound modes. In an active nematic, activity instead causes topological disclinations to become spontaneously motile, which can drive defect unbinding and organize novel phases of defect order and chaos. In all three cases, geometric and topological ideas enable the relevant degrees of freedom to be identified, allowing complex phenomena to be treated in a tractable fashion, with novel and surprising consequences along the way.

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### Pulsars as Weber Gravitational Wave Detectors -- Ajit Srivastava

Apr 8, 2019, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

A gravitational wave (GW) passing through a pulsar will lead to a variation in the moment of inertia of the pulsar affecting its rotation. This will affect the extremely accurately measured spin rate of the pulsar as well as its pulse profile. The effect will be most pronounced at resonance and should be detectable by accurate observations of the pulsar signal. The pulsar, in this sense, acts as a remotely stationed Weber detector of gravitational waves whose signal can be monitored on earth. With possible GW sources spread around in the universe, pulsars in their neighborhoods can provide us a family of "remote" detectors all of which can be monitored on earth. An important implication of this results is that it allows us to revisit already detected GW events via pulsars, thus giving the possibility of further information about the GW source, along with the information of pulsar interior. This can help in better triangulation of the GW source location, which will be of crucial importance for sources which do not emit any other form of radiation such as black hole mergers. Importantly, pulsars may allow us to detect those events whose direct signals reached earth in past, hence were missed. We consider different GW events and list specific pulsars whose signals will carry the imprints of these events in future, to be specific we constrain it within 100 years. Interestingly, we find cases where the perturbed pulsar signal could reach earth within next 10-20 years.

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### Collective behavior underlying the mechanobiology of cells and tissues, by Moumita Das

Apr 5, 2019, 11:00 AM-12:00 PM

202 Physics Bldg.

Host: Prof. Alison Patteson / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Living cells and tissues are highly mechanically sensitive and active. Mechanical stimuli influence the shape, motility, and functions of cells, modulate the behavior of tissues, and play a key role in several diseases. In this talk I will discuss the structure function properties of biopolymer networks in cells and tissues that arise due to the interplay of their micro-structure, mechanics, and statistical mechanical properties. In particular, I will focus on the heterogeneity and composite nature of these biological systems and their proximity to phase transitions. I will start with articular cartilage (AC), a soft tissue mainly made of network like extra-cellular matrix. AC covers the ends of long mammalian bones, serving to minimize friction and distribute mechanical loads in joints. It is a remarkable tissue: it can support loads exceeding ten times our body weight and bear 60+ years of daily mechanical loading despite having minimal regenerative capacity. I will discuss the physical principles underlying this exceptional mechanical response and crack resistance in AC, and compare our theoretical predictions with experimental results. The second focus of my talk consists of the dynamic mechanical response of actin networks. Actin is a key component of the cytoskeleton essential to cell growth, division, shape change, and motility. To enable this wide range of mechanical processes and properties, networks of actin filaments continuously disassemble and reassemble via active de/re-polymerization. I will discuss how de/re-polymerization kinetics of individual actin filaments translate to experimentally observed time-varying mechanical properties of dis/re-assembling networks. Understanding the mechanical structure function properties of these systems will provide insights into the dynamic response, toughness, and failure of biopolymer networks in cells and tissues, tissue repair therapies, and design principles for soft robotics.

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### Relevant Operators of Particle Physics and Cosmology

Apr 5, 2019, 10:00 AM-11:30 AM

Room 208 Physics Bldg.

Although the Standard Model of Particle Physics can reproduce the results of all the experiments performed to this date, it can only be an effective theory of fundamental physics. However, treating the Standard Model this way brings its own set of challenges; namely, the coefficients of relevant operators become extremely sensitive to UV physics. The relevant operator of the Standard Model is the Higgs mass which causes the "hierarchy problem", while the cosmological constant term of cosmology results in the "cosmological constant problem". In this thesis defense, I will talk about how these issues can guide us in the pursuit of searching for new physics, both from a model building perspective and from a phenomenological perspective. In the first part, I will present a Higgs model on a five-dimensional Anti-de-Sitter space which attempts to make the Higgs criticality a dynamical attractor of the theory, thereby eliminating the sensitivity to the UV parameters. In the second part, I will talk about how we can gain some insights about the cosmological constant problem from the observations of binary neutron star mergers.

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### What Stubs and Sparkles In Vast Vats of Liquid Will Tell Us About Exploding Stars by Kate Scholberg

Apr 4, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Denver Whittington. Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

When a massive star collapses at the end of its life, nearly all of the gravitational binding energy of the resulting remnant is released in the form of neutrinos.  I will discuss the nature of the core-collapse neutrino burst and what we can learn about particle physics and about astrophysics from the detection of these neutrinos. I will cover supernova neutrino detection techniques in general, current supernova neutrino detectors, and prospects for specific future experiments.

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### Holography, large N, and supersymmetry on the lattice by Raghav Jha

Apr 2, 2019, 2:45 PM-4:00 PM

Room: 202 Physics Bldg.

The lattice studies of strongly coupled gauge theories started with the pioneering work of Wilson. The success of lattice QCD over the decades has improved our understanding of the strong dynamics, crucial for a proper understanding of many interesting phenomena in Physics. However, it is now known that the Standard Model of particle physics is only an approximation to some richer underlying theory. It is believed that supersymmetry has a special role to play in the framework of such a theory. Even if nature is non-supersymmetric at all energy scales and we don’t see any experimental evidence in the coming decades, the beautiful structure of these theories and the great failure could still be very important lessons in our quest to understand the universe. In four dimensions, one particular supersymmetric theory has drastically altered our understanding of the holographic principle. In view of these observations, the study of supersymmetric theories on the lattice at strong couplings is crucial. Even though lattice supersymmetry has a long history going back four decades, it has been very difficult to simulate four-dimensional theory at strong couplings till date. This is because supersymmetry on the lattice is far from being trivial because of the supersymmetric algebra. However, substantial progress has been made in studying these theories on the lattice over the past decade. Several wonderful ideas like topological twisting, Dirac-Kahler fermions, differential forms, point group symmetries of the lattice all come together and has enabled us to study these supersymmetric theories by preserving a subset of supersymmetries exactly on the lattice. In this thesis defense talk, I will discuss numerical studies of super Yang-Mills (SYM) theories in various dimensions with insights about their large N limit and the relation to gauge/gravity dualities.

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### Salam – The First ****** Nobel Laureate

Mar 29, 2019, 7:00 PM-9:00 PM

Joyce Hergenhan Auditorium, 140 Newhouse 3

##### New Documentary shines light on Pakistan’s great forgotten genius: Nobel Prize winning physicist, Abdus Salam

“Salam” is the definitive story of Abdus Salam – the first Pakistani to win the Nobel Prize. The film captures in vivid detail his life’s journey and his fraught relationship with his homeland, as he faced oppression, rejection and exile for being a member of the Ahmadiyya faith.

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### Talk by Raghav

Mar 29, 2019, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Judah

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### Crowd Control-- biophysical approaches to understand and 'herd' cells within living tissues, by Daniel Cohen

Mar 29, 2019, 11:00 AM-12:00 PM

Room 208 Physics Bldg.

Host: Prof. Lisa Manning / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Multicellular life is driven by collective cell behaviors spanning morphogenesis, growth, healing, and even cancer invasion.  Our work draws on biophysics, swarm theory, cell biology, and bioengineering to develop new tools to both better understand and interactively control such behaviors—much as a shepherd and sheepdog herd sheep. The first part of this talk will present data from our recent work exploring questions such as how the size and shape of ‘large’ monolayer tissues affect their outgrowth. Next, we will discuss our two key control paradigms for controlling collective cell behaviors. Our ‘Outside-In’ paradigm leverages ‘electrotaxis’ to allow us to program and remote control collective cell migration in real-time and we will discuss our most recent data characterizing the extent of this control. In contrast, our ‘Inside-Out’ approach taps into the cell-cell adhesion network within a tissue through the use of ‘cell-mimetic’ biomaterials that incorporate cadherin proteins to effectively trick cells into forming hybrid junctions with the material as if it were another cell. In the long-term, we hope to combine our biophysical understanding of how collective behaviors work with a control theoretic approach to better grow and heal tissues.

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### Accepted Graduate Students Visiting Day

Mar 29, 2019, 9:00 AM-6:00 PM

Room: 202/204 Physics Bldg.

Stefan Ballmer/ Melissa Wike - mawike@syr.edu

The Syracuse University Physics department is excited to host our annual Visiting Day for Admitted Students on March 29th. We look forward to meeting the admitted graduate class for Fall 2019 and introducing them to some of the exciting experiences available through our department.

View the tentative schedule

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### Shape Sculpting and Shapeshifting in Soft Matter by Tim Atherton

Mar 28, 2019, 3:30 PM-3:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Joseph Paulsen, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Soft materials are ideal candidates for advanced engineering applications including soft, biomimetic robots, self-building machines, shape-shifters, artificial muscles, and chemical delivery packages. In many of these, the material must make a dramatic change in shape with an accompanying re-ordering of the material; in others changes in the ordering can be used to drive or even interrupt shape change. To optimize the materials and structures, it is necessary to have a detailed understanding of how the microstructure and macroscopic shape co-evolve. In this talk, I will therefore discuss the interactions between order and shape evolution, as well as the role of the kinetics in determining the final state, with examples primarily drawn from my group's work on emulsions. To develop the description, we draw upon differential geometry, topology, optimization theory and computer simulations, and connect our results to other work on jamming and crystallography on curved surfaces

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Mar 26, 2019, 1:00 PM-2:30 PM

Room: 202/204 Physics Bldg.

LIGO was built with the purpose of detecting the ripples in space-time caused by astrophysical events with the hopes of understanding the complexities hidden within the cosmos. In 2011, the primary stages of Advanced LIGO were installed and commissioned to start the first observing run (O1). Following that time, the detectors had hardware replaced in order to mitigate noise from scattered light and new optics which reduced the losses from absorption. The upgrades were in preparation for the third observing run (O3) and the work presented here is primarily focused on experimental techniques for operating at higher power and mode matching Gaussian beams in the dual-recycled Michelson interferometer for the Advanced LIGO era and beyond.

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### Talk by Brendon

Mar 22, 2019, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Judah

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### Balancing Forces at Adhesions: How Cells Sense Stiffness, by Patrick Oakes

Mar 22, 2019, 11:00 AM-12:00 PM

Room: 202 Physics Bldg.

Host: Prof. Jennifer Schwarz / Contact: Yudaisy Salomón Sargentón, 315-443-5960

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### The mechanics of origami by Chris Santangelo

Mar 19, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Lisa Manning, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

The ancient art of folding paper has re-emerged as a new frontier in the fabrication of complex three-dimensional structures from flat substrates. In this talk, I will review the state of the art in creating self-folding structures from initially flat substrates, and describe our theoretical progress understanding the mechanics of folding and folded devices. This understanding has allowed us to rationally design a variety of devices from thin sheets. Finally, I will highlight the challenges that remain in realizing origami as a tool for advanced manufacturing and some of the promising future directions.

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### Talk by Nouman

Mar 8, 2019, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Judah

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### New Gravitational Probes of Dark Matter -- Evan McDonough

Mar 1, 2019, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Scott Watson/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Despite decades of searching, the strongest evidence for dark matter remains gravitational. It is thus worthwhile to consider the extent to which gravitational probes can discriminate between models of cold dark matter. With this in mind, in this talk I will discuss the early universe origins and late universe observables of "superfluid" dark matter. Despite having only gravitational couplings to the standard model, this scenario provides a suite of complimentary observable signatures. A concrete model realization is SU(2) gauge theory with two massless quarks: At finite particle number density and low temperature, the dark quarks condense and form a superfluid, the collective excitations of which behave as cold dark matter. The associated early universe production of gravitational waves can be probed by the CMB, while halo substructure in the form of vortices and disk-like solitons leaves a characteristic imprint on strong gravitational lensing. Talk based on arXiv:1801.07255 and arXiv:1901.03694.

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### The cost of crushing: curvature-driven wrinkling of thin elastic shells

Feb 26, 2019, 4:00 PM-5:00 PM

Carnegie 122

Joint Mathematics/Physics Colloquium - Joseph Paulsen: jdpaulse@syr.edu

How much energy does it take to stamp a thin elastic shell flat? Motivated by recent experiments on wrinkling patterns formed by thin floating shells, we develop a rigorous method (via Gamma-convergence) for evaluating the cost of crushing to leading order in the shell’s thickness and other small parameters. The observed patterns involve regions of well-defined wrinkling alongside totally disordered regions where no single direction of wrinkling is preferred. Our goal is to explain the appearance of such “wrinkling domains”. Our analysis proves that energetically optimal patterns maximize their projected planar area subject to a shortness constraint. This purely geometric variational problem turns out to be explicitly solvable in many cases of interest, and a strikingly simple scheme for predicting wrinkle patterns results. We demonstrate our methods with concrete examples and offer comparisons with simulation and experiment.

This talk will be mathematically self-contained, not assuming prior background in elasticity or calculus of variations.

Dr. Tobasco is a candidate for a position in Mathematics under the Bio-enabled Science & Technology cluster proposal.There will be coffee and cookies in room 111 Carnegie at 3:30pm, Feb 26.

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### Talk by Judah

Feb 22, 2019, 12:00 PM-1:00 PM

208 Physics Bldg.

Host: Judah

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### Push and pull: Mechanical forces that guide cell motility, by Alison Patteson

Feb 22, 2019, 11:00 AM-12:00 PM

202 Physics Bldg.

Host: Prof. Lisa Manning / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Mechanical effects can have as great an influence on cell structure and function as signaling by chemical stimuli. Many cell types alter their morphology or change their motility patterns when grown on substrates of different stiffness, confined by external boundaries, or reach critical densities that give rise to collective motion. I will discuss two general problems. The first regards how alterations of the mammalian cytoskeleton maximize motility in vivo without compromising cellular integrity. The second, how active swarms of bacteria utilize collective motion to capture new territory at the boundary of dead passive matter. Our results highlight the need for theoretical and experimental research to address emerging questions related to non-equilibrium living matter.

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### Chaotic Dynamics from Fuzzy Spheres -- Seckin Kürkçüoğlu

Feb 18, 2019, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

We examine the Yang-Mills matrix models with a mass deformation term and determine explicit SU(4) equivariant parametrizations of the gauge field and the fluctuations about the classical fuzzy four sphere configurations and obtain the dimnsonally reduced actions by tracing over the fuzzy spheres for the first five lowest matrix levels. These reduced systems exhibit chaos, which we reveal by computing their Lyapunov exponents. Using our numerical results, we explore various aspects of the emerging chaotic dynamics. In particular, we model how the largest Lyapunov exponents change as a function of the energy.

The talk is based on the recent article JHEP12(2018)015 with Ü. H. Coşkun, G.C. Toga & G. Ünal.

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### Talk by Cem

Feb 15, 2019, 12:00 PM-1:00 PM

208 Physics Bldg.

Host: Judah

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### Chirality-induced helical self-propulsion of chiral liquid crystal droplets, by Takaki Yamamoto

Feb 15, 2019, 11:00 AM-12:00 PM

202 Physics Bldg.

Host: Prof. Lisa Manning / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Artificial microswimmers have been intensively studied to understand the mechanism of the locomotion and collective behaviors of cells and microorganisms. Among them, most of the artificial microswimmers are designed to swim along the straight path. However, in biological systems, chiral dynamics such as circular and helical motions are quite common because of the chirality of their bodies. To understand the role of the chirality in the dynamics of microswimmers, we designed an experimental system [1] and the phenomenological model [2] of a self-propelled chiral liquid crystal (CLC) droplet dispersed in a surfactant solution which swims in a helical path driven by the Marangoni flow. In [1] and [2], we speculated that CLC droplets swim in helical paths due to the chiral coupling between translational motion induced by the Marangoni flow and rotational motion via the chirality of helical director fields in the CLC droplets. However, such a chiral coupling has not been verified by experimentally observing hydrodynamic flow which the CLC droplets produce. Thus, the mechanism of the helical motion of CLC droplets remains to be elucidated from the viewpoint of hydrodynamics.

In the experimental system of swimming CLC droplets, we recently found that, under a condition, the droplets do not exhibit translational motion but only rotational motion, driven by the concentration gradient of surfactant around the droplet, which occurs due to the effect of gravity [3]. In this study, to obtain a clue to the mechanism of the helical motion of CLC droplets from the viewpoint of hydrodynamics, we investigated the hydrodynamic flow around the rotating CLC droplets. Consequently, we revealed that a nontrivial rotational hydrodynamic flow appears around the rotating CLC droplets. While the mechanism of the rotation and the generation of the hydrodynamic flow is not fully understood, we would like to discuss these experimental results and the roles of chirality in active matter.

[1] T. Yamamoto and M. Sano, Soft Matter, 13, 3328 (2017).
[2] T. Yamamoto and M. Sano, Phys. Rev. E., 97, 012607 (2018).
[3] T. Yamamoto and M. Sano, under review.

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### The Spectacular Start of Multi-Messenger Gravitational Wave Astronomy by Wolfgang Kastaun

Feb 14, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Brown/Ballmer, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Maybe the single most exciting events in astronomy during the recent years have been the first detections of gravitational waves by the

LIGO/Virgo scientific collaboration. One event, likely caused by the coalescence of two neutron stars, was also observed by a large number of conventional telescopes throughout the electromagnetic spectrum, from gamma rays over visible light to radio waves. After an introduction to gravitational waves, black holes, and neutron stars, I will summarize our current understanding of what happens when neutron stars merge. Next, I will explain how it is possible to detect  the tiny effects of gravitational waves. Finally, I give an overview of the first observation of a binary neutron star merger with both electromagnetic and gravitational waves, and the insights that can be gained by this new window into the universe.

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### Bright, Electromagnetic Counterparts to Supermassive Black Hole Mergers by Eric Coughlin

Feb 12, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Duncan Brown, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Recent observations of a neutron star-neutron star merger verified -- in striking agreement with theoretical predictions -- that the gravitational waves emitted from such a merger are accompanied by an electromagnetic signature, which itself is bright from gamma-rays (the gamma-ray burst), to optical/UV (the kilonova), to radio (the afterglow). The corresponding electromagnetic signature from the inspiral of two supermassive black holes, the gravitational waves from which will be detectable in the upcoming era of space-based interferometry, is less clear. However, any potential signature and its detectability are likely determined by the distribution of gas around the black holes, and the dynamic response of that gas to the mass lost to gravitational waves during the final coalescence. In this talk, I will describe a mechanism responsible for generating a quasi-spherical, pressurized bubble'' of gas that enshrouds a supermassive black hole binary during the final years of its merger. I will show that the mass lost to gravitational waves initiates the formation of a pressure wave within this bubble, which steepens into a shock very near its surface. The breakout of this shock then powers a luminous, electromagnetic transient that can peak and fade on timescales of months to years. I will discuss these results in the context of the electromagnetic detectability of supermassive black hole binary mergers.

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### Talk by Kenny

Feb 8, 2019, 2:00 PM-3:00 PM

208 Physics Bldg.

Host: Judah

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### Developing membrane protein based nanopore for real-time sensing of transient protein-protein interaction (PPI) at the single molecule level by Avinash Thakur

Feb 8, 2019, 1:00 PM-4:00 PM

Room: 202/204 Physics Bldg.

Transient Protein-protein interactions (PPIs) are essential for numerous cellular processes. Existing methods used for PPI studies provide only ensemble-averaged molecular information and are often restricted in the range of kinetic rate constants they can precisely measure. In this talk, I will illustrate an experimental approach, where a membrane protein has been engineered as a quantitative nanopore sensor for detecting and analyzing transient PPIs in real time at the single-event resolution. Our designed sensing approach could be multiplexed by incorporating sensors into existing flow cells and microfluidic devices, thereby, enabling the development of high-throughput drug screening and point-of-care diagnostic tools.

CM

### Mechanisms for failure in granular packings under applied shear and beyond, by Peter Morse

Feb 8, 2019, 11:00 AM-12:00 PM

202 Physics Bldg.

Host: Prof. Lisa Manning / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Under shear, a jammed packing of particles will begin to break and create contacts as the packing transitions between mechanically stable states. Interestingly, changes in the contact network do not always require a change in state, meaning most simple contact changes are reversible. When a system does undergo a structural rearrangement, many of the signatures of the *transitions* between states exhibit robust finite size scaling, suggesting that perhaps the transition between disordered mechanically stable states has some characteristics of a real phase transition, as has been previously postulated. The scaling also indicates that the zero-pressure limit is singular and suggests that the low-frequency excitations of the system at zero pressure may be different from those in finite-pressure systems, which would strongly impact the rheology of sheared systems. Finally, we extend this work to understand if shear strain is special, or whether arbitrary random strains applied to a packing yield similar scaling in critical properties. I will define a more general type of random force perturbation, with connections to active matter, and show that random forcing yields critical behavior that is very similar to that of shear.

C

### Cosmology with gravitational waves by Ema Dimastrogiovanni

Feb 7, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Duncan Brown, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

In this talk I describe possible implications, for cosmology as well as high energy physics, of the detection of a stochastic primordial gravitational waves (PGW) background. I discuss the prospects for constraining a compelling new class of early universe scenarios known as axion-gauge field inflation. The PGW spectrum originating from these set-ups has strikingly different features with respect to those from the minimal inflationary scenario.The existence of these models calls for of a precise characterization of the primordial gravitational waves signal: in order to fully exploit the potential of PGW for the discovery of new physics, we must clearly identify their sources.

C

### Big Bang vs. Big Bounce by Anna Ijjas

Feb 5, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Duncan Brown, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

For over fifty years, since the discovery of the cosmic microwave background, the consensus view has been that the universe had a definite beginning, known as the big bang. In this talk, I will review the standard inflationary paradigm and how it is supposed to explain the large-scale structure of our universe. We will then consider whether it is possible to replace the big bang with a big bounce, discarding the idea of a “beginning” altogether and perhaps obtaining a more natural explanation of the large-scale properties of the observable universe.

CM

### What do guitar strings and balloons have in common with biological tissues? by Lisa Manning

Feb 1, 2019, 11:00 AM-12:00 PM

202 Physics Bldg.

Contact: Yudaisy Salomón Sargentón, 315-443-5960

Both guitar strings and balloons are floppy unless rigidified by geometrically induced self-stresses. Similar kinds of rigidity transitions have recently been described in biopolymer networks and cellular biological tissues, and recent work suggests that these rigidity transitions are utilized to regulate and drive morphogenesis. Here, we propose a general, geometric approach to quantitatively describe such transitions. Based on a minimal length function, which scales linearly with intrinsic fluctuations in the system and quadratically with shear strain, we make concrete predictions about the elastic response of these materials, which we verify numerically and which are consistent with previous experiments.  Our approach may provide a gateway towards connecting macroscopic rheological properties of acellular and cellular biological tissues to their microscopic structure, and thereby to cell-level signaling processes in morphogenesis.

C

### Quantum measurement and metrology with a mechanical oscillator by Vivishek Sudhir

Jan 31, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

The precision measurement of position has a rich heritage in physics. A 100 years ago,
debate surrounding the atomic hypothesis was settled by careful measurements of the thermal
(“Brownian”) motion of particulate matter. Today, similar measurements of random position
fluctuations, but with a 17 orders of magnitude improvement in sensitivity, witness the vacuum
fluctuations (“zero-point motion”) of nanoscopic objects. These advances, rooted in the pursuit
of gravitational wave detection, hope to measure the position of a macroscopic object with the
minimum noise allowed by the principles of quantum mechanics.
I shall present details of a series of experiments, performed over the past few years,
where this hope has largely been realized. In these experiments, the fundamental vibrational
mode of a glass nanostring is measured using an interferometric sensor with a precision that is
sufficient to force a confrontation with the predictions of the uncertainty principle. We are able
to observe the concomitant back-action of the measurement, and use feedback control to cancel
it. We are also able to observe the generation of quantum correlations in the light exiting the
interferometer. These non-classical correlations form a useful resource that can be used for
metrological gain: we demonstrate that they can be used for a quantum enhancement of the
force sensitivity of a room-temperature interferometer, via coherent back-action cancellation.
Finally, I will report on the realization of strong radiation pressure coupling between a
0.25 kg mechanical oscillator and light stored in a meter-long interferometer. These experiments
herald the possibility of quantum measurement of Planck-mass-scale objects on the table-top.

S

### Else Lasker-Schüler's Modernist Poetry - Translations by Brooks Haxton - A Reading

Jan 30, 2019, 3:45 PM-4:45 PM

202 Physics Building

Eric Schiff

The poet Brooks Haxton has published a bilingual book of translations of Else Lasker-Schüler’s poetry. A century ago Lasker-Schüler was among the most prominent of the modernist German poets. She also had a notoriously Bohemian lifestyle. Nonetheless, in 1932 she was awarded Germany’s highest literary honor, the Kleist-Preis. A year later, she left Germany forever. Her art, lifestyle, and Jewish heritage were intolerable to the new Nazi regime. Her poetry is highly original and influential.

The hour will include an introduction to Lasker-Schüler, Haxton's readings from his translations, and Karina von Tippelskirch’s readings from the German originals.

C

### From Stellar Dynamics to Compact Binaries: Unlocking the Future of Gravitational Waves

Jan 29, 2019, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Duncan Brown, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Since the first detection over three years ago, gravitational waves have promised to revolutionize our understanding of compact objects, binary evolution, general relativity, and cosmology. But to make that a reality, we need to understand how and where these relativistic binaries form.  In this talk, I will describe the various astrophysical pathways for creating the binary mergers detected by LIGO/Virgo, and how specific features of the gravitational waves (such as the binary eccentricities and black hole spins) can shed light on the formation of these dark remnants.  I will show how simple gravitational dynamics makes the centers of dense star clusters, particularly globular clusters, uniquely efficient at producing merging binaries.  Finally, I will talk about the future of the field, and how gravitational-wave astronomy is poised to offer us unprecedented insights into physics, astrophysics, and cosmology over the coming years and decades

TD

Jan 29, 2019, 1:30 PM-3:30 PM

Room: 202/204 Physics Bldg.

Advanced LIGO is commissioning new noise reducing technologies that are sensitive to optical losses like mode mismatch. Optical cavity mode mismatch can be reduced by the use of adaptive optics, wavefront sensors, and feedback control loops. Advanced LIGO currently has the ability to dynamically correct optical cavity misalignment, but lacks equality capable hardware for mode matching. Presented is a possible upgrade that will allow for sensing optical cavity mode mismatch and alignment while introducing minimal hardware. The working principle behind this upgrade begins with the understanding that a mode mismatched optical cavity generates a Laguerre-Gauss bullseye mode. A cylindrical lens mode converting telescope can then optically convert the bullseye mode into a rotated Hermite-Gauss pringle mode. The rotated mode is perfectly shaped for detection by the existing quadrant photodiode wavefront sensors and can then be used to generate a feedback error signal. Additionally, the upgrade explores the use of an annular heated thermal lens actuator combined with a high sensitivity telescope as a mode matching actuator. This combination increases the actuation capabilities and hence can be a viable actuator if currently installed mode matching actuators do not provide sufficient range.

### New Physics from Quantum Information Theory by Dr. Mohammad Ansari

Jan 17, 2019, 11:00 AM-12:00 PM

Room: 202 Physics Bldg.

Host: Britton Plourde. Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

In quantum physics physical quantities are linear in density matrix, e.g. energy, current, spin, etc. However, this is not the case in quantum information theory as  informational measures are nonlinear functions in density matrix; examples are entropy, fidelity loss, purity, etc.  Is there any way to measure information in the lab using physical quantities? This is an important question that I’ll address in this talk. I’ll present a new correspondence between entropy and physical quantities. I will  discuss how this correspondence may introduce new physics in quantum heat engines, quantum computation, black holes, etc..

HE

### Talk by Raghav

Dec 7, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Judah

C

### New simulations and observations of highly-complex molecules in star-forming regions by Robin Garrod

Dec 6, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Gianfranco Vidali, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

The interstellar medium (ISM) is replete with molecules, and high-mass star-formation regions in particular are host to some of the most complex organic molecules yet detected outside of our solar system. Millimeter/sub-millimeter wavelength spectral data from the ALMA telescope allows us to explore the chemistry of such regions in much greater detail than ever before. The ALMA 3mm line survey EMoCA ("Exploring Molecular Complexity with ALMA") of the chemically-rich Galactic Center source Sagittarius B2(N) has not only identified several new molecules in that source, but has led to the identification of new molecule-rich hot cores - a total of five are now known to exist in Sgr B2(N).

I will give a brief overview of the molecular detections made by EMoCA toward Sgr B2(N). I will also present chemical kinetics models of the coupled gas-phase and grain-surface/ice-mantle chemistry occurring in Sgr B2(N) related to these molecules, with an emphasis on the treatment of the recently-detected branched carbon-chain molecule iso-propyl cyanide (i-C3H7CN). I will assess the possibilities for the presence and detectability of other branched carbon-chain molecules in the ISM. I will also present recent work that uses complex molecule abundances to constrain the cosmic-ray ionization rates and chemical timescales within different hot cores.

HE

### Observing the leptonic flavour breaking scale at colliders and direct searches -- Jessica Turner

Nov 30, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Jack Laiho/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The observed pattern of mixing in the neutrino sector may be explained by the presence of a non-Abelian, discrete flavour symmetry broken into residual subgroups at low energies. These flavour models require the presence of Standard Model singlet scalars, namely flavons, which can promptly decay to charged leptons in a flavour-conserving or violating manner. In this talk, I will present the constraints on the model parameters of an A4 leptonic flavour model using a synergy of g-2, charged lepton flavour conversion and collider data. The most powerful constraints derive from the MEG collaboration's result on mu to e gamma and the reinterpretation of an 8 TeV ATLAS search for anomalous productions of multi-leptonic final states.

HE

### Talk by Nick & Merrill

Nov 30, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Judah

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### The Kameshwar C. Wali Lecture in the Sciences and Humanities: US Nuclear Weapons Policy: 'Time for the Concerned Public to Intervene Again' by Dr. Frank von Hippel

Nov 29, 2018, 4:00 PM-5:30 PM

SHAFFER ART BLDG AUDITORIUM

Coordinator: Prof. Simon Catterall. Contact: Yudaisy Salomon Sargenton

The last massive intervention by the concerned public in U.S. nuclear weapons policy was by the grassroots Nuclear Weapons Freeze Movement and its European counterpart in the early 1980s. One result was to shift the U.S. government from insisting that the Soviet Union believed it possible to fight and win a nuclear war, and therefore so must we; to repeated joint summit statements by Presidents Gorbachev and Reagan that “nuclear war cannot be won and must never be fought.” More tangibly, the result was a reduction in the global stock of nuclear warheads from about 65,000 in 1991 to about 10,000 today. The effect has worn off, however, and two separate but related nuclear arms races have begun: between the U.S. and Russia and the U.S. and China, plus proliferation crises with the “rogue” states, North Korea and Iran. The perverse dynamics underlying these crises will be explained and possible initiatives to mitigate them will be discussed, including a:

• U.S. no-first use policy,
• Restoration of limits on ineffective but provocative ballistic missile defenses,
• Resumption of US-Russian nuclear reductions along with a cap on China’s nuclear buildup,
and
• Strengthening the nonproliferation regime with bans on the separation of plutonium and on
national uranium enrichment capabilities.

Finally, the effectiveness of activist citizens teamed up with scientists for “credibility” working to educate Congress – as in the “Freeze” movement – will be recounted.

HE

### Talk by Asad & Kenny

Nov 16, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Judah

C

### Searching for the secrets of the non-linear Universe by Tom Giblin

Nov 15, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Scott G. Watson, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

We have no evidence that general relativity is wrong; every precision test is a resounding confirmation of this elegant and powerful mathematical model.  Trouble is: the greatest cosmological problems of our time (likely require) us to abandon general relativity.  About 95% of the Universe remains a mystery whose solution evades our abilities.  I will talk about how there may still be places in general relativity that have, until now, gone unexplored.  Numerical simulations are a powerful tool that can model the complex non-linear issues of general relativity on cosmological scales.  I will present progress that we have made toward modeling the late Universe in its full splendor and outline where there’s hope that we can start to tackle these great questions.

HE

### Pairwise Perturbative Ansatz for Quantum Process Tomography by Luke Govia

Nov 12, 2018, 2:00 PM-3:00 PM

Room: 202/204 Physics Bldg.

Host: Matt LaHaye. Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

As candidate quantum processors increase both in size and fidelity, so too does the need for robust verification and validation of their operation. Full characterization of these devices would be highly desirable; however, standard quantum process tomography scales exponentially with the number of qubits. Even for small scale systems, the experimental resource requirements make full tomography very challenging in practice. To circumvent this, we have developed an ansatz to describe an arbitrary quantum process on a multi-qubit system that only requires characterization of two-qubit processes, such that the number of measurements scales only quadratically with the number of qubits. Our Pairwise Perturbative Ansatz (PAPA) builds a description of the multi-qubit process from tomographic reconstruction of the reduced two-qubit processes on all pairs of qubits in the system. This talk will consist of a brief overview of quantum process tomography, followed by an outline of the PAPA approach and the results of theoretical simulations showing how PAPA can be used for excellent characterization of multi-qubit quantum processes.

HE

### The Tachyonic Instability in Scalar-Tensor Theories -- Georgios Papadomanolakis

Nov 9, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Scott Watson/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

In recent years the discovery of late-time cosmic acceleration triggered the creation of a landscape of extensions of General Relativity, aimed at providing a theoretical compelling mechanism. Now, with the wealth of current and upcoming observational data, it becomes imperative to find efficient ways to constrain these theories both from a theoretical as a data point of view. In this talk I will start by introducing the formalism of the Effective Field Theory of Dark Energy and Modify Gravity and will then proceed to employ it in order to study the theoretical stability of scalar extensions of gravity. I will pay special attention to the tachyonic instability, an instability seldom taken into account in the literature. This will yield powerful new constraints that severely impact the parameter space of gravitational theories. In the final part I will present how they impact the phenomenological (μ,Σ) parameter space, a result obtained by implementing the stability conditions in the Einstein Boltzmann solver EFTCAMB.

C

### The shape-shifting ghosts of the standard model and how we study them by Alex Himmel

Nov 8, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Denver Whittington. Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Neutrinos are the second most numerous particle in the universe, but one of the least understood. Every day, trillions pass through us without us noticing. We need to produce them in enormous quantities and create building-sized detectors in order to see them.  When we do, they exhibit an unusual quantum mechanical behavior called "oscillations:" a neutrino of one "flavor" will change to a different flavor, and back again, as it travels. We study oscillations because they may be a window to deeper mysteries like the matter-antimatter asymmetry in the universe or what physics lies beyond the standard model. In this colloquium, we'll explore the physics of neutrino oscillations and how to measure them, looking at two particular experiments: the NOvA experiment, which running right now, and the next-generation replacement, DUNE.

HE

### Talk by Bharath

Nov 2, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Judah/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

HE

### TBA Jim Halverson/Brent Nelson

Oct 26, 2018, 2:00 PM-3:00 PM

208 Physics Bldg.

Host: Scott Watson/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

C

### A Brief History of Stephen Hawking by Prof. Scott Watson

Oct 25, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Kamesh Wali. Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

HE

### Black Holes, and Nuggets, and Blobs. Oh my! -- Andrew Long

Oct 22, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Scott Watson/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The past few years have seen a growing interest to explore dark matter candidates that are outside of the standard WIMP paradigm. A resurgence of macroscopic dark matter candidates have brought with it a mix of whimsical names — primordial black holes, asymmetric dark matter nuggets, and dark blobs — to name a few. In general the difficulty with macro dark matter is not the observational constraints, which are typically quite sparse and weak, but rather the challenge is finding a well-motivated mechanism for producing gram-sized dark matter objects. In this talk, I will argue that “dark quark nuggets” are a generic prediction of confining, hidden-sector gauge theories. I will discuss the phenomenology of these theories, the cosmological production of dark quark nuggets, and their observational probes.

HE

### Talk by Cem

Oct 19, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Judah/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

C

### The Proton Radius Puzzle by Evangeline Downie

Oct 18, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Steven Blusk/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The Proton Radius Puzzle is the difference between the radius of the proton when measured with electrons, and that measured with muons. Its potential resolutions could be very exciting, include beyond-standard-model physics. Its impact is broad as the uncertainty in the proton radius is the leading cause of uncertainty in many other areas of physics. The puzzle has resulted in several papers in Science and Nature, and much popular media interest. It began in 2010 with an ultra-precise radius measurement by the CREMA collaboration using muonic hydrogen, which produced a proton radius result roughly 7 standard deviations away from the accepted value. This caused a flurry of theory development, new experiments, and much thought and discussion. The radius puzzle remains unresolved to this day, with many new experiments proposed and under development and hotly debated theories. We will give an overview of the Puzzle, its potential implications and resolutions, and an overview of the ongoing experimental efforts to understand the discrepancy in a quantity of relevance for many areas of physics.

HE

### Cosmological Observables via Nonequilibrium Quantum Dynamics in Nonstationary Spacetimes -- Mahmoud Parvizi

Oct 12, 2018, 2:00 PM-3:00 PM

208 Physics Bldg.

Host: Scott Watson/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

A covariant description of quantum matter fields in the early universe underpins models of inflation and dark matter production with implications for moduli fields of type IIB orbifold compactifications treated in the low energy limit. In nearly all cases the relevant cosmological observables are computed via a general approximation to the standard irreducible representations found in the operator formalism of particle physics, where intricacies related to a renormalized stress-energy tensor in a nonstationary spacetime are ignored. Models of the early universe also include a dense environment of quantum fields where far-from-equilibrium interactions manifest expressions for observables with substantive corrections to the leading terms. A more rigorous treatment of these cosmological observables may be carried out within the alternative framework of algebraic quantum field theory in curved spacetime, where the field theoretic model of quantum matter is compatible with the classical effects of general relativity. Hence, we employ the algebraic formalism while considering far-from-equilibrium interactions in a dense environment under the influence of a classical, yet nonstationary, spacetime to derive an expression for the time-dependent energy density as a component of the renormalized stress-energy tensor.

HE

### Primordial black holes -- Alex Kusenko

Oct 5, 2018, 2:00 PM-3:00 PM

208 Physics Bldg.

Host: Scott Watson/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

I will discuss some ideas for the cosmological origin of black holes and their possible role as dark matter.

C

### Black holes gold rush

Oct 4, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Scott G. Watson, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

Recent discoveries promise to revolutionize our understanding of black holes, their origin, and their signals.   I will discuss the signals observed from giant black holes in remote galaxies, as well as the possibility that small black holes created in the early universe make up the cosmological dark matter and contribute to synthesis of heavy elements, including gold.

HE

### The Causal Set Path Integral -- Sumati Surya

Oct 1, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Causal set theory (circa 1987, Syracuse) lends itself naturally to the path integral formulation of quantum gravity. A continuum inspired dynamics for causal sets uses the discrete Einstein-Hilbert or Benincasa-Dowker action in the path sum over causal sets. Using an analytic continuation without a Wick rotation, this path sum can be cast into a partition function for Lorentzian statistical geometry, thus making it amenable to numerical evaluation. We consider a 2d restriction of the theory and evaluate expectation values of covariant observables (which correspond to order invariants) using standard Markov chain Monte Carlo techniques. In the topologically trivial sector, the system has been shown to exhibit a first order phase transition. Recent work using ideas from lattice gas models show that this phase transition survives more generally. I will end by discussing some recent ideas and preliminary results on incorporating topology change in this theory, enroute to a more complete theory of 2d causal set quantum gravity.

HE

### Superfluids and the cosmological constant problem -- Adam Solomon

Sep 28, 2018, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Scott Watson/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The old cosmological constant problem - why do we not see the gravitational effects of the large vacuum energy predicted by particle physics? - is an outstanding problem for cosmologists, relativists, and particle physicists alike. One possibility is that gravity is modified in such a way that the cosmological constant does not gravitate the way it does general relativity, though there are few (if any) concrete and realistic models along these lines. I will discuss a simple theory which takes a significant step towards accomplishing this goal by admitting stable Minkowski solutions in the presence of an arbitrarily large cosmological constant, without introducing obvious pathologies or contradictions with experiment. The model consists of a quartet of scalar fields invariant under internal time-dependent spatial diffeomorphisms. Physically, this can be seen equivalently as either a theory of Lorentz-violating massive gravity or of a finite-temperature superfluid pervading the Universe, dynamically cancelling out the energy density of a cosmological constant.

HE

### Talk by Brandon

Sep 21, 2018, 2:00 PM-3:30 PM

208 Physics Bldg.

Judah: jfunmuth@syr.edu

C

### Testing the Hydrogen Bomb: A Status Report by Emlyn Willard Hughes

Sep 20, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Paul Souder, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

In the 1940s and 1950s, the United States performed 67 nuclear weapon tests in the Marshall Islands, including the detonation of the largest US thermonuclear weapon (15 megatons), named Castle Bravo. Seventy years later, the impact of these tests on the Marshallese people is still apparent. The more recent challenge of rising sea levels, coupled with the remaining nuclear waste represents a particularly chilling problem. In this talk, we will discuss our recent work on this topic, as well as future plans.

HE

### Self-Organized Higgs Criticality -- Jay Hubisz

Sep 17, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

I will discuss an approach to the scalar hierarchy problem that draws on concepts that have so far been primarily applied to certain dynamical systems. These are systems that are naturally driven to critical points and are maintained there by dynamical internal adjustment (i.e. by avalanche phenomena, slippage, etc). Motivated in part by conjecture and experimental hints that some such systems exhibit log periodic scaling associated with complex valued scaling dimensions, I will discuss a 5 dimensional dual to a renormalization group trajectory that runs towards a regime of approximate discrete scale invariance. Such behavior is forbidden as a "healthy" trajectory, and is dual to an emergent Breitenlohner-Freedman tachyon instability for scalar fields in AdS space. We explore how bulk 5D physics responds to this instability, and how this model might simultaneously relate to the lightness of the Higgs and issues of cosmology through a mechanism akin to frustration in condensed matter systems.

HE

### Talk by Gabriele

Sep 14, 2018, 2:00 PM-3:30 PM

208 Physics Bldg.

Judah: jfunmuth@syr.edu

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### Proposals for a Syracuse Open Access policy for research publications

Sep 13, 2018, 3:30 PM-4:30 PM

Room: 202/204 Physics Bldg.

Host: Eric Schiff. Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

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### Physics Department Annual Fall Picnic

Sep 9, 2018, 11:00 AM-3:00 PM

Green Lakes State Park, Reserve Shelter

Contact: Yudaisy Salomón Sargentón, 315-443-5960

Please join us on Sunday, September 9th, 2018 for the Physics Department Fall Picnic at Green Lakes’ Reserve Shelter. There will be food, there will be games, there will be fun!

*Please note that cleanup is starts at 3 pm. Guests are welcome to stay longer if they so wish. Note that this it is a ‘carry-in carry-out park.

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### "What we talk about when we talk about strings" by Xi Yin

Sep 6, 2018, 3:30 PM-3:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Scott G. Watson, Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

I will discuss what relativistic strings are, where they come from, why they exist, and what we can learn from and about them.

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### Teaching Assistant Training

Aug 20, 2018, 8:30 AM-3:30 PM

See schedule attached

The Physics Department is hosting its Teaching Assistant Training from Monday, August 20th through Thursday, August 23rd.

The event will kick off with our Annual Pancake Breakfast (all faculty, staff and students are welcome to this event) followed by a variety of activities directed to new graduate students and teaching assistants.

The annual Adventure Course + Team Building Activity will take place the last day of training for all new graduate students.

Please find a detailed schedule of events below:

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### Annual Pancake Breakfast

Aug 20, 2018, 8:30 AM-5:00 PM

Room: 202/204 Physics Bldg.

Host: Sam Sampere. Contact: Yudaisy Salomon Sargenton - phyadmin@syr.edu

The Physics Department is hosting the Annual Pancake Breakfast on Monday, August 20, 2018. All graduate students, faculty and staff are invited. Please come and meet our new graduate students in a fun, relaxed atmosphere. A delicious hot breakfast will be served.

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### Comprehensive Exam

Aug 18, 2018, 2:00 PM-4:00 PM

Room: 202/204 Physics Bldg.

Prof. Matt Rudolph

There are two examinations given in August. All new graduate students must take the comprehensive exam. You may choose to attempt the qualifying examination – email phyadmin@syr.edu if you would like to take it. Second year students take the qualifying examination. Both examinations have two parts: one on Saturday, one on Sunday.

Saturday, August 18 & Sunday, August 19: ALL INCOMING STUDENTS, 202/204 Physics Building
2:00 p.m. – 4:00 p.m. Comprehensive Exam (Matthew Rudolph)
Part I – Saturday; Part II -­‐ Sunday

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### Qualifying Exam

Aug 18, 2018, 9:00 AM-12:00 PM

Room: 202/204 Physics Bldg.

Prof. Paul Souder, Liviu Movileanu, Jack Laiho

There are two examinations given in August. All new graduate students must take the comprehensive exam. You may choose to attempt the qualifying examination – email phyadmin@syr.edu if you would like to take it. Second year students take the qualifying examination. Both examinations have two parts: one on Saturday, one on Sunday.
Saturday, August 18 & Sunday, August 19 202/204 Physics Building-9:00 a.m. – 12:00 noon Qualifying Exam (Paul Souder, Liviu Movileanu, Jack Laiho)

TD

### "Understanding Nonequilibrium Behaviors of Spin Glasses Through Heuristics" by Jie Yang

Aug 14, 2018, 1:00 PM-2:30 PM

Room: 202 Physics Bldg.

Spin glass behavior was first seen in metallic alloys with magnetic impurities dispersed randomly in the main non-magnetic component. Due to the simultaneous presence of quenched disorder and competing ferromagnetic and antiferromagnetic interactions, the nonequilibrium behaviors of spin glasses are intricate and difficult to understand. This dissertation introduces efficient algorithms and heuristics for the numerical simulation of simple models for spin glasses and discusses significant simulation results. The results provide insights into understanding the nonequilibrium behaviors, especially aging and memory, through studying microscopic constitent configurations.

TD

### "Dispersive Transport and Drift Mobilities in Methylammonium Lead Iodide Perovskites" by Brian Maynard

Aug 13, 2018, 10:00 AM-11:30 AM

Room: 202 Physics Bldg.

Perovskite solar cells (PSCs) have impacted the photovoltaic industry over the past decade with unprecedented boosts in photo-conversion efficiencies. Perovskites dramatic rise was due to borrowed ideas and research from other types of solar cell geometries. The initial surge in perovskite research started in 2009 with the discovery of unusually long photocharge carrier lifetimes and ambipolar diffusion. These discoveries changed the geometry of the solar cell from a dye-sensitized structure to n-i-p. The work done in this dissertation focuses on thin film methyl-ammonium lead iodide perovskites in n-i-p structures made by the National Renewable Energy Laboratory and Iowa State University. The initial goal of this research was to use photo carrier time-of-flight measurements to determine the value of the drift mobility in the perovskite.  I found evidence of dispersive transport for both photocharge carriers which came as a surprise. I was the first to make transient temperature dependent studies of the drift mobility and the dispersion parameter, under otherwise normal device operating conditions. The low values of the electron and hole drift mobilities, ~10-1 cm2/Vs, under operating conditions suggest that the optimal thickness of the perovskite layer can be determined via calculation. Unfortunately, the dispersive nature of perovskite thin films makes such calculations complicated. I propose, based on the temperature dependent studies of my work, that photocharge transport in perovskite thin films are spatially dispersive.

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### Early Universe Constraints from Primordial Black Holes and Cosmological Limits on Quantum Mechanics by Julian Georg

Aug 9, 2018, 3:00 PM-4:30 PM

Room: 208 Physics Bldg.

In this dissertation we study how to constrain early universe models by their prediction of Primordial Black Hole formation. Furthermore we also explore the possibility that the produced Primordial Black Holes can constitute all or part of the dark matter. Lastly, we present an analysis where we use cosmological data to put limits on a non linear extension of quantum mechanics.

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### Rheology and Collective Behavior in Living Tissues by Michael Czajkowski

Aug 7, 2018, 10:00 AM-11:30 AM

Room: 202 Physics Bldg.

Recent experiments and simulations have indicated that confluent epithelial layers, where there are no gaps or overlaps between the cells, can transition from a floppy fluid-like state to a rigid solid-like state, with dynamics that share many features with glass transitions. While a coherent picture has begun to form connecting the microscopic causes of this transition with the macroscopic observables and expectations, much less is known of its consequences in biological processes. Do tissues tune themselves to a glassy state in order to promote collective motion? Has evolution made use of this behavior in programming the complex steps leading from the embryo to the organism? Here, our recent efforts to answer such questions at the continuum and microscopic level are described in detail. Employing the biophysical vertex model, active confluent groupings of cells are described as polygons with shape-based energies. This same modeling technique played a key role in uncovering the signatures of glassy states in these tissues, and in our first effort we extend the model to include the influence of cell division and cell death. With careful analysis, we are able to refute a recent claim that the presence of such division and death will always eliminate glassiness. We then extend these findings to explore the influence of open boundaries on these tissues, identifying the necessary ingredients for sustained tissue expansion. Finally, we develop a novel hydrodynamic model that describes confluent motile tissues. This development is enabled by the apparent (and unprecedented) existence of a structural order parameter for glassiness in tissues. Our formalism enables investigation of how feedbacks between tissue stiffness and cell migration (which we term “morphotaxis”) lead to pattern formation in confluent tissues. We find that a specific “morphotactic” parameter controls whether a tissue will remain homogeneous or will develop patterns such as asters and bands

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### Haozhi Wang

Aug 2, 2018, 1:00 PM-5:00 PM

room and number

Superconducting circuits operated at low temperatures have led to rapid advances in quantum information processing as well as quantum optics in the microwave regime. Engineered quantum systems with a dense spectrum of modes coupled to artificial atoms, or qubits, formed from superconducting circuits offer an opportunity to explore largescale entanglement or perform quantum simulations of many-body phenomena. Recent research efforts into artificial metamaterials have yielded microwave and optical systems with numerous counterintuitive properties, including left-handed transmission, where the group velocity and phase velocity for a wave point in opposite directions. Metamaterial resonators implemented with superconducting thin-film circuits provide a route to generating dense mode spectra in the microwave regime for coupling to qubits. In this thesis, we discuss the implementation of such superconducting metamaterial resonators. First, we derive the dispersion relation for one-dimensional metamaterial transmission lines and we describe the formation of resonators from such lines and their quality factors. Next, we describe the design and fabrication of transmission-line metamaterial resonators using superconducting thin films. We characterize the metamaterials through low-temperature microwave measurements as well as Laser Scanning Microscope (LSM) images of the microwave field distributions in the circuit. We compare these various measurements with numerical simulations of the microwave properties of the circuits, including simulated current density and charge density distributions for the excitation of different resonance modes. Following the successful realization of dense mode spectra in these circuits, we have initiated the first experiments with a superconducting transmon qubit coupled to a metamaterial resonator and we describe our progress in this direction.

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### "Motility-induced phases: out-of-equilibrium droplets, surfaces, and survival" by Adam Patch

Jul 31, 2018, 11:00 AM-12:30 PM

Room: 202 Physics Bldg.

Active matter represents a unique out-of-equilibrium matter endowed with motility, the ability of each individual unit to move according to its own self-propulsion force. Objects of study in active matter include entities like birds in flight or cells in confluence, which become particularly interesting at scales larger than the individuals, where groups display emergent collective behavior like flocking and morphogenetic self-organization. One can study both microscopic and macroscopic behaviors of these particles using theory, simulation, and experiment, but largescale simulations are critically important to understanding some of the underlying statistical mechanical properties of active matter.

My work has focused on Motility-Induced Phase Separation (MIPS), a unique example of out-of-equilibrium emergent behavior, in which a fluid of active particles with repulsive-only interactions use their motility to spontaneously separate into coexisting dense and dilute phases. In this emergent collective behavior, particles nucleate stable clusters that eventually coarsen and coalesce into system-spanning bulk phases that stabilize in a steady state, much like nucleation and spinodal decomposition in liquid-gas phase coexistence. In this defense I will present work I have done studying the fundamental physics of MIPS through simulations of large ensembles of Active Brownian Particles (ABPs), from which I directly measure quantities like pressure, surface tension, density, currents, and cluster growth exponents for comparison to continuum models and experiments. I present results regarding pressure and kinetics of MIPS and its uniquely out-of-equilibrium surface "tension". Additionally, I present work done in collaboration with biologists studying the self-assembly of a soil-dwelling bacteria, Myxococcus xanthus, whose cells utilize collective behavior to form aggregates known as fruiting bodies, which are nascent structures critical to the survival of M. xanthus colonies. While bacteria are inherently more complex than ABPs, we have shown that the onset of fruiting body formation is remarkably similar to MIPS at larger scales.

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### Statistical mechanics of thermalized ribbons and sheets by Sourav Bhabesh

Jul 6, 2018, 9:00 AM-11:00 AM

Room: 202/204 Physics Bldg.

Host: Prof. Mark Bowick/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

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### TBD by Swetha Bhagwat

Jun 29, 2018, 3:00 PM-4:30 PM

Room: 202/204 Physics Bldg.

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### Solid-Solid Phase Transitions in Colloidal Matter by Chrisy Xiyu Du

May 17, 2018, 9:00 AM-10:00 AM

Room 208

Host: Lisa Manning (mmanning@syr.edu)

Phase transitions are ubiquitous in nature, and are observed throughout everyday life from the melting of ice to the magnetization of iron. In particular, solid–solid phase transitions are important in many areas such as metallurgy, geosciences, and the design of reconfigurable materials. Following the recent initiative of using nano building blocks to design next generation materials, we answer fundamental questions about solid–solid phase transitions in colloidal matter and guide the design of materials that can change phase. We construct a minimal model of solid–solid phase transitions that are induced by altering particle shape. Using the minimal model, we are able to determine the thermodynamic order of several phase transitions. Under the same construct of the minimal model, we can also design target phase transitions as desired. Our results show viable candidate particles for reconfigurable materials. Moreover, our results give insight into the fundamental of the most common, but most poorly understood phase transitions in nature, and provide new minimal models for understanding solid–solid transitions in atomic systems.

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### Cosmological Perturbations in the Early Universe by Gizem Sengor

May 11, 2018, 11:30 AM-12:30 PM

Room 208 Physics Building

A key essence of capturing the history of primordial fluctuations that arise during inflation and eventually lead to formation of large scale structures in the universe on paper, relies on quantizing general relativity coupled to a scalar field. This is a system that respects diffeomorphism invariance, the freedom of choosing the coordinate system to work with without changing the physics. Hence the way to handle its quantization requires a well understanding of how to quantize diffeomorphisms. Deciding on suitable coordinate choices and making sure that this gauge fixing, which is unavoidable in any calculation, does not effect the end result is tricky. In this thesis we make full use of the effects of diffeomorphism invariance of the theory on the primordial fluctuations to pursue two different approaches that focus on treating perturbations after gauge fixing. On one line we work towards developing our understanding of how to handle quantization in terms of Dirac quantization and Becchi, Rouet, Stora, Tyutin (BRST) quantization. On another line we focus on how to generalize the allowed interactions and understand the scales they bring in the era of preheating that follows inflation, with effective field theory methods on cosmological backgrounds

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### Observing black holes and neutron stars from across the universe with gravity by Dr. Josh Smith

May 3, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof.Duncan Brown/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Gravitational waves, ripples in space-time, provide a view of the universe complimentary, and often completely invisible, to light. In 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) debuted this new ”sense” for humanity by observing gravitational waves from coalescing binary systems of black holes. In 2017, LIGO and Virgo kicked off an era of multimessenger gravitational-wave astronomy by observing a binary neutron star merger and prompting electromagnetic observations across the electromagnetic spectrum. These discoveries have solved the mysterious origins of short gamma-ray bursts, provided new tests of relativity, measurements of the Hubble constant, and insights into black hole and neutron star physics. I will discuss these results and how advances in gravitational-wave observing technology beyond this initial breakthrough will open other frequency bands of the unexplored gravitational-wave spectrum and probe the universe’s structure and history on cosmological scales.

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### Taking the measure of neutron stars with NICER -- Simin Mahmoodifar

Apr 30, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Jack Laiho/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The Neutron Star Interior Composition Explorer (NICER) is NASA's new X-ray timing instrument onboard the ISS that was launched in June 2017. With a large effective area, low background, very precise absolute timing and great low energy response, NICER has been doing a fantastic job in observing many interesting phenomena related to neutron stars and black holes. One of the main goals of the NICER mission is to constrain the equation of state of ultra-dense matter by measuring the masses and radii of several rotation-powered millisecond pulsars. This is being done by fitting pulse waveform models that incorporate all relevant relativistic effects and atmospheric radiation transfer processes to the periodic soft X-ray modulations produced by the rotation of hot spots located near the magnetic polar caps of these pulsars. Some of the other interesting topics that are being studied with NICER includes phenomena related to Type I X-ray bursts, which are thermonuclear flashes observed from the surfaces of accreting neutron stars in Low Mass X-ray Binaries, such as photospheric radius expansion and burst oscillations. NICER's large effective area and excellent low energy response enable new, detailed studies of these bursts in the soft X-ray band. In this talk I will present some of the early results from the first nine months of the NICER mission and will report on the progress being made by the NICER team in measuring the masses and radii of pulsars.

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### TBA Thomas Grégoire

Apr 27, 2018, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Jay Hubisz/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

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### Shape Sculpting and Shapeshifting with Soft Matter by Tim Atherton

Apr 27, 2018, 11:00 AM-12:00 PM

Room 202/204

Host: Joey Paulsen | Contact: David Yllanes (dyllanes@syr.edu)

Soft materials are ideal candidates for advanced engineering applications including soft, biomimetic robots, self-building machines, shape-shifters, artificial muscles, and chemical delivery packages. In many of these, the material must make a dramatic change in shape with an accompanying re-ordering of the material; in others changes in the ordering can be used to drive or even interrupt shape change. To optimize the materials and structures, it is necessary to have a detailed understanding of how the microstructure and macroscopic shape co-evolve. In this talk, I will therefore discuss the interactions between order and shape evolution, as well as the role of the kinetics in determining the final state, with examples primarily drawn from my group's work on emulsions and liquid crystals. To develop the description, we draw upon differential geometry, topology, optimization theory and computer simulations, and connect our results to other work on jamming and crystallography on curved surfaces.

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### Soft-matter mechanics of biofilm infections: What is the impact on resistance to the immune system? by Vernita Gordon

Apr 26, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Lisa Manning/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Biofilms are aggregates of microbes that are bound together by a matrix of polymer and proteins.  Biofilms produce chronic, sometimes decades-long, infections that resist clearance by the immune system.  Biofilms are viscoelastic solids, with resistance to deformation that is roughly comparable to the mechanical forces exerted by phagocytosing immune cells.  We have recently shown that in vivo evolution of chronic infections promotes mechanical toughness and stiffness (2017 npj Biofilms and Microbiomes).  Now, we present ongoing work examining how the mechanics of a soft, viscoelastic target impacts the ability of immune cells to break up and clear that target - this topic has not been studied before, so we have developed new experiments to measure this, using human neutrophils.  We also are also examining approaches to disrupting biofilm mechanics, with a view toward developing treatments that make biofilm infections more amenable to clearance by the immune system.

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### An effective model for light composite scalars in multiflavor gauge theory -- Yannick Meurice

Apr 24, 2018, 10:00 AM-12:00 PM

202 Physics Bldg.

Host: Judah Unmuth-Yockey/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

It is expected that when the number of light flavors of QCD-like theories is increased beyond some critical value, scalars particles with a mass much smaller than the dynamical scale appear. We describe this situation with a linear sigma model. Using lattice results, we found combinations of the masses of scalars and pseudoscalars that vary slowly with the explicit chiral symmetry breaking.  The term representing the axial anomaly plays a leading role in the mass spectrum.  We estimate the critical number of flavors for which the sigma becomes massless in the chiral limit.  We discuss the  possible relevance for composite Higgs model. Details can be found in PRD 96, 114507.  Recent progress with 2 different masses will be discussed.

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### A tensorial toolkit for quantum computing in lattice gauge theory -- Yannick Meurice

Apr 23, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Judah Unmuth-Yockey/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

We introduce the tensor renormalization group method for spin and gauge lattice models.  We show that it is the ideal tool for coarse graining and  performing quantum simulations.  We discuss a concrete proposal to emulate the Abelian Higgs model with optical lattices.  We answer frequently asked questions about boundary conditions, truncations, symmetries, topology and Grassmann tensors.

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### A natural generalization of the standard Randall-Sundrum framework and its phenomenological implications -- Sungwoo Hong

Apr 20, 2018, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Judah Unmuth-Yockey/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

In the first part of the talk, I will introduce a very natural extension of well-motivated extra-dimensional framework of Randall-Sundrum type. Such a generalization is motivated by (null) results from both high energy (LHC) and low energy (flavor, CP, and electroweak precision) experiments. In particular, null results from the LHC led us to consider the possibility that little hierarchy may exist. In addition to the consistency with low energy bounds, our generalization can address the question of the form of TeV scale new physics we can expect. I will argue that such new physics appearing at the TeV scale is in the form of vector-like confinement with new states interacting with SM through mostly flavor universal couplings. In the second part of the talk, I will discuss several exciting signals probable at the LHC and in future colliders.

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### Towards a mechanobiological framework to simulate the life cycle of the human brain by Johannes Weickenmeier

Apr 20, 2018, 11:00 AM-12:00 PM

Room 202/204

Host: Jen Schwarz | Contact: David Yllanes (dyllanes@syr.edu)

The brain is our most complex organ and provides tremendous scientific opportunities for engineering disciplines, and computational solid mechanics in particular; yet, despite the obvious role of mechanics in understanding traumatic injuries and the progression of neurodegenerative diseases, brain mechanics remains understudied. My research integrates experimental and computational methods to investigate the life cycle of the human brain, with a particular interest in the biophysics of traumatic brain injury and the progression of neurodegenerative diseases, such as Alzheimer’s disease and chronic traumatic encephalopathy.

This talk will elaborate on my brain tissue experiments and numerical simulations of the mechanical response during trauma. A series of in-vivo, in-situ, and ex-vivo measurements using indentation testing and magnetic resonance elastography demonstrated the impact of local tissue composition and metabolic brain activity on the (visco)elastic brain tissue response. On the computational side, I developed an anatomically accurate finite ele0ment model of the head to simulate traumatic and degenerative brain diseases. Through the examples of excessive brain swelling after a stroke and the propagation of toxic proteins through the brain in dementia, I will delineate brain regions exposed to critical loads and at risk of long-term neurodegeneration. These models provide a promising biophysics-based computational framework to systematically investigate the onset, progression, and treatment of brain related injuries.

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### Seeking Signs of Ancient Life on Mars by Sarah M. Milkovich

Apr 19, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Steven Blusk/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

For hundreds of years, the idea of an inhabited Mars has captured our imaginations, but our first close-up view of Mars showed it to be a cold, barren desert. For decades, NASA has been exploring Mars with a fleet of spacecraft to understand the role of water in its history and look for areas that in the past could have supported life. This work has paved the way for the upcoming Mars 2020 rover – which will search for clues concerning the existence of life itself on Mars in the past.

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### Self-propelled particle modeling, characterization, and imaging of superdiffusive fibroblast cells on 2D shape memory polymer substrates by Giuseppe Passucci

Apr 18, 2018, 2:00 PM-4:00 PM

Room: 202 Physics Bldg.

Most important biological processes involve cell motion; breast carcinoma cells metastasize throughout a body, epithelial cells spread to close a wound, T-cells rushing to fill their immune response duties. The list of essential phenomena is nearly endless, as is the corresponding number of biochemical signaling pathways and other biological features that mediate cell-cell and cell-environment interactions. Understanding these phenomena through the characterization of genetics and biological signaling is a fruitful, bottom-up approach. A complementary approach uses tools from condensed matter and statistical physics to quantify and make predictions about cells and interactions between them. For example, statistical metrics such as mean-squared displacement or velocity auto-correlation functions help characterize the behavior of cell populations with no knowledge of their specific biochemical interactions. These tools were utilized to determine the mechanism behind superdiffusivity in mouse fibroblast cells. This work shows that a generalized heterogeneous self-propelled particle model captures mouse fibroblast trajectory dynamics by replacing parameters in simulations (speed, rotational diffusion, tumble frequency) with appropriate distributions. Additionally, in order to quantify the intracellular orientation of mouse fibroblast cells, I developed robust imaging software which identifies and tracks Golgi bodies. When paired with the appropriate and already tracked nucleus, this yields a definition of cell orientation. After automating this software, we characterized the mechanoresponse of mouse fibroblast cells on static and active 2D shape memory polymer substrates. While the direction of cell nuclei elongation became more aligned after the SMPs were triggered to form wrinkles, as seen previously, the orientation defined by the Golgi body-nucleus axis aligned with the future wrinkle direction even before visible wrinkles were triggered, suggesting intracellular orientation is more sensitive to the environment than previously thought. In summary, this body of work represents novel investigations into the dynamics of mouse fibroblast cells in 2D as well as software contributions for imaging irregular objects in biological data.

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### Relaxed Inflation -- Walter Tangarife

Apr 16, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Jay Hubisz/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The cosmological relaxation of the electroweak scale has been proposed as a mechanism to address the hierarchy problem of the Standard Model. A field, the relaxion, rolls down its potential and, in doing so, scans the squared mass parameter of the Higgs. In the original proposal, the rolling takes place in the background of inflation, which provides constant Hubble friction. In this talk, I will present our proposal, in which we promote the relaxion to an inflaton, and in addition we couple it to Abelian gauge bosons. This introduces a new dissipation mechanism, crucial to slow down the field in the last stages, and allows for reheating at the end of inflation. I will discuss the cosmological dynamics of the model and the phenomenological constraints from CMB and other experiments.

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### Measurements of Beauty Production Cross-Sections and Fragmentation Ratios using the LHCb Detector by Matthew Kelsey

Apr 13, 2018, 3:00 PM-4:00 PM

Room: 202/204 Physics Bldg.

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### A link between asymptotically safe gravity and Standard Model matter -- Aaron Held

Apr 13, 2018, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Jack Laiho/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Renormalization Group flows provide a link between Planck- and electroweak-scale physics, that could allow to test implications of quantum gravity at accessible energy scales. Systematic truncations suggest the existence of a regime of asymptotic safety, in which gravity fluctuations could induce a UV-completion of the matter sector. Within this scenario, the paradigm of asymptotic safety surpasses the predictive power of the Standard Model: It could retrodict the top and bottom mass from first principles in a microscopic model including quantum gravity. Assuming no new physics below the Planck scale, we construct explicit Renormalization Group trajectories for Standard Model and gravitational couplings which link the transplanckian regime to the electroweak scale and yield a top pole mass of approximately 170 GeV. Unequal quantum numbers lead to different fixed-point values for the top and bottom Yukawa under the impact of gauge and gravity fluctuations at an interacting fixed point. In our approximation, quantitative agreement with observations points towards an electric charge ratio of bottom and top in close vicinity to the Standard-Model value of Qb/Qt=-1/2.

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### Quantum optics with van der Waals heterostructures by Nick Vamivakas

Apr 12, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Matt LaHaye / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Two-dimensional, atomically-thin, materials have received enormous interest as a result of their unique mechanical, electrical and optical properties.  Particularly exciting are the transition metal dichalcogenides – atomically-thin semiconductors that possess an electronic band gap in the visible.  Although these materials have been investigated for applications in opto-electronics, not much work has focused on these systems as a platform for quantum photonics and quantum optics.  In this talk I will describe two approaches that leverage atomically thin semiconductors, and other two-dimensional materials, assembled in layered van der Waals heterostructures for applications in these areas. In the first part of the talk I will describe the unique photophysical properties of quantum emitters hosted by single layer transition metal dichalcogenides. I will describe our recent efforts to controllably charge the quantum emitters and realize a localized spin-valley-photon interface. I will also present results on realizing negative-mass trion-polaritons that are a manifestation of many body physics arising when coupling the atomically thin semiconductor to a planar optical cavity.

Bio: Nick Vamivakas studied electrical engineering at Boston University and received his PhD degree in 2008. Following his PhD, he was a post-doc from 2007-2011 in the Cavendish Laboratory at the University of Cambridge. Nick joined the Institute of Optics in 2011 and currently is an associate professor.

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### Observation of cosmic ray multiple-muon seasonal variations in the NOvA Near Detector by Stefano Tognini

Apr 11, 2018, 3:00 PM-4:00 PM

Room: 202 Physics Bldg.

Host: Prof. Mitch Soderberg/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

"The collision of a cosmic ray particle with the Earth's atmosphere produces what it is known as an extensive air shower (EAS), which is a cascade of particles produced due to a chain of interactions and decays throughout the atmosphere that may reach deep underground depths. Such events have been studied since the early twentieth century and play an important role in our understanding of the Earth's climate, chemical composition, life evolution, and aerospace travel.

Muons are a large fraction of the particles produced during an EAS, whose high penetrative power allows the study of cosmic ray physics using deep underground detectors. The dynamics of these EAS are tightly connected to the conditions of the atmosphere and, as such, the average number muons produced during an EAS suffers a yearly seasonal effect that follows atmospheric seasonal temperature changes. In 2015 the MINOS Experiment showed that said modulation trend inverts for more energetic cosmic rays, disagreeing with theoretical predictions. In this scenario, a study with the goal to verify the MINOS result and further understand the phenomenon was carried forward by the NOvA Experiment."

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### Effects of asymptotically safe gravity on matter models -- Fleur Versteegen

Apr 9, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Jack Laiho/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

We explore the impact of asymptotically safe quantum gravity on the Abelian gauge coupling in a model including a charged scalar, confirming indications that asymptotically safe quantum fluctuations of gravity could trigger a power-law running towards a free fixed point for the gauge coupling above the Planck scale. Simultaneously, quantum gravity fluctuations balance against matter fluctuations to generate an interacting fixed point, which acts as a boundary of the basin of attraction of the free fixed point. This enforces an upper bound on the infrared value of the Abelian gauge coupling. In the regime of gravity couplings which in our approximation also allows for a prediction of the top quark and Higgs mass close to the experimental value, we obtain an upper bound approximately 35% above the infrared value of the hypercharge coupling in the Standard Model.

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### Swarms and plant root growth - Collective behavior in biology by David Quint

Apr 6, 2018, 11:00 AM-12:00 PM

Room 202/204

Host: Jen Schwarz | Contact: David Yllanes (dyllanes@syr.edu)

Throughout my career, including my graduate work at Syracuse University, I've had the pleasure of working on a wide range of interesting biologically inspired physics problems. In this talk, I will present two projects that represent the range of that work. The first part of my presentation will focus on understanding how swarms or flocks deal with intrinsic disorder in their environment, such as physical obstacles, while maintaining a swarm-like state. The second part of my talk will focus on plant root growth in the model plant system Arabidopsis thaliana. It has been believed for some time that internal pressure of the cell, derived from an imbalance of osmolytes, drives cell expansion and thus tissue growth.  Using a novel microfluidic system I have shown that osmotic (turgor) pressure seems to be unimportant for the maintenance and growth of plant cells in root tissue. This result has provided clues in regards to mechanical feedback mechanisms for tissue growth in plant roots.

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### Connecting Digital Computers to Quantum Processors by Prof. Britton Plourde

Apr 5, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Contact: Yudaisy Salomón Sargentón, 315-443-5960

Quantum computers make use of some of the counterintuitive properties of quantum mechanics, including superpositions of states and entanglement, to process information. A large-scale quantum processor could solve problems that are intractable on conventional computers. Superconducting circuits based on Josephson junctions are one of the leading candidates for the quantum bits, or qubits, of a quantum computer and systems with more than 50 qubits are just becoming available this year. Building significantly larger arrays of qubits and interfacing them with digital coprocessors will require new techniques for preparing and measuring the qubits without substantial hardware overhead. I will describe our ongoing efforts to integrate superconducting classical digital circuitry with superconducting qubits for coherent control and measurement.

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### Two Tales of Exo-Planets: Atmospheric Evaporation and The Astrobiology of the Anthropocene by Adam Frank

Mar 29, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Peter Saulson/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

In this two-part talk I present results from our group studying exoplanets as physical systems as well as using them to consider future evolutionary pathways for human civilization on a climate-changed world.  In the first part of the talk I will report on results using Adaptive Mesh Refinement radiation hydrodynamic simulations to study exoplanet “winds” created by photoionization from the parent star.  Such mass loss can dramatically change a planet’s atmospheric evolution.

In the second part of the talk I will introduce new work on "The Astrobiology of the Anthropocene” where we develop models showing climate change to be the likely generic outcome of an exo-civilization's co-evolution with it’s home planet.  We show how this “astrobiological perspective” might inform current debates about the long term viability of a civilization like our own.

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### Low-lying scalar mesons on and off the lattice -- Joel Giedt

Mar 26, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Some scalar mesons are narrow and have been established since the 1960s, whereas others are so broad that they remain somewhat controversial.  Isoscalar mesons in particular raise various theoretical questions, especially since they can mix with glueballs.  In this talk I will review some of the experimental evidence for scalar mesons below about 1.6 GeV, especially the so-called sigma meson. I will describe some of the theoretical models that have been put forward for the internal structure, or partonic content, of these mesons.  Then I will discuss lattice studies that have been performed to investigate these issues. A description of the methods that have been employed will be given.  Finally, I will discuss our on-going research into the isoscalar scalar mesons using four-pion correlation functions, including our recently published estimate from a quenched calculation.  Since much of our computation uses graphical processing units (GPUs), I will also describe how this modern architecture enables calculations that were not previously possible due to the significant cost-performance benefits of this technology.

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### Using b-fusion to investigate B-anomalies at the LHC -- Bhaskar Dutta

Mar 23, 2018, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Scott Watson/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Anomalies in B-meson decays reported by the LHCb experiment imply a new  second-third generation mixing among quarks. We use b-fusions to probe and investigate a possible reach at the LHC for these scenarios utilizing  new final states. This technique can be utilized for any model with new physics associated mostly to the second and third generation SM quarks.

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### Adaptive coding for sensory inference in dynamic environments by Ann Hermundstad

Mar 23, 2018, 11:00 AM-12:00 PM

Room 202/204

Host: Lisa Manning | Contact: David Yllanes (dyllanes@syr.edu)

Making reliable inferences about the environment is crucial for survival. In order to escape a hawk, for example, a mouse might need to infer the hawk’s position and velocity from patterns of light that fall on its retina.  Such inferences require large ensembles of sensory neurons whose activity is metabolically expensive. A growing body of evidence suggests that sensory systems reduce metabolic costs by limiting the fidelity with which some stimuli are encoded in neural responses. Limited coding fidelity, however, can lead to inaccuracies in inference. Here, we derive a framework for dynamically balancing the cost of encoding with the error that encoding can induce in inference. We model a system that must use minimal metabolic resources to maintain an accurate estimate of a nonstationary environment, and we show that the optimal system should adapt the fidelity with which stimuli are encoded in neural responses based on a changing estimate of the environment. We use this framework to illustrate how a range of neuronal and behavioral phenomena can be understood as signatures of adaptive encoding for accurate inference.

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### Spinning topology in ordered and amorphous metamaterials by Noah Mitchell

Mar 19, 2018, 2:00 PM-3:00 PM

Room 208

Host: Joey Paulsen | Contact: David Yllanes (dyllanes@syr.edu)

Topology has emerged as a powerful tool for understanding a wide range of phenomena in condensed matter physics. Whether electronic, optical, or mechanical, materials with topological order in their excitation spectra exhibit unique behaviors at their boundaries, such as chiral edge currents that are unusually robust to disorder. In this talk, we uncover topological behavior in a simple system composed of interacting gyroscopes and use this metamaterial to explore broken symmetries and tune through topological phase transitions in real time. We then peel away a canonical ingredient for constructing topological insulators: the ordered underlying lattice. Here, we find topological physics emerging from amorphous networks of gyroscopes and establish the basic building blocks for understanding topology in amorphous systems. The results apply to a broad class of systems, from electronic and photonic materials to acoustic and mechanical structures.

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### Shearing structurally disordered systems: revisiting mean-field descriptions by Elisabeth Agoritsas

Mar 16, 2018, 11:00 AM-12:00 PM

Room 202/204

Host: Lisa Manning | Contact: David Yllanes (dyllanes@syr.edu)

Structurally disordered systems, when submitted to an external deformation such as a constant shear, are known to exhibit a nonlinear response, signature of an out-of-equilibrium phase transition. This highly nontrivial behaviour depends in fact crucially on the intensity of the external driving, which triggers randomly local plastic rearrangements throughout the system, thus constantly updating its local disordered energy landscape. Linking on the one hand the collective behaviour of these local plastic events, and on the other hand the macroscopic nonlinear response, represents a challenging issue from the statistical physics point of view of driven disordered systems.
Several mean-field elasto-plastic' models have been developed, at a mesoscopic scale defined by the typical size of individual plastic events. These mean-field descriptions have proven to be rather successful in reproducing certain features observed in sheared disordered systems, but not all at once; moreover, a consistent picture connecting them is still missing. Here I will discuss the physical ingredients that are put in such mean-field models, in particular the assumptions underlying the effective stochastic process defining them. I will focus on the steady-state response of athermal systems, when the velocity of the deformation (i.e. shear rate) is controlled, discussing specifically the so-called Hébraud-Lequeux’ model and its generalisations.

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### Multimessenger astrophysics with numerical relativity by David Radice

Feb 26, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof.Duncan Brown/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

How are neutron stars formed and what is inside them? What is the  engine powering short gamma-ray bursts? What is the astrophysical site  of production of heavy elements? Multimessenger observations of compact binary coalescence and core-collapse supernovae might provide  us with the key to answer these and other important open questions in theoretical astrophysics. However, multimessenger astronomy also poses  new challenges to the theorists who need to develop models for the  joint interpretation of all data channels. In this talk, I will  present recent theoretical results. I will review the landmark multimessenger observation of merging neutron stars, and I will discuss its interpretation and implication in the light of results from first-principles simulations. Finally, I will discuss future challenges and prospective for this nascent field.

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### Hairy Interfaces by Alice Nasto

Feb 23, 2018, 11:00 AM-12:00 PM

Room 202/204

Host: Joey Paulsen | Contact: David Yllanes (dyllanes@syr.edu)

Textured surfaces are known to play an important role in water-repellency and uptake for a number of creatures. While the influence of chemistry and surface roughness on the wettability of surfaces has been studied extensively, little is known about the role of larger objects such as hairs. Our work is directed towards rationalizing the benefits gained from hairy textures through a combined experimental and theoretical approach.

First, we are motivated by semi-aquatic mammals, who rely on fur for insulation underwater. We investigate the mechanism of dynamic air entrainment for hairy surfaces plunged in liquid. Hairy surfaces that are fabricated using laser cut molds and casting samples with PDMS are plunged into a fluid bath. Modeling the hairy texture as a network of capillary tubes, the imbibition speed of water into the hairs is obtained through a balance of hydrostatic pressure and viscous stress. The maximum diving depth that can be achieved before the hairs are wetted to the roots is predicted from a comparison of the diving speed and imbibition speed.

Second, motivated by nectar-drinking animals with hairy tongues, we investigate the reverse scenario, where a hairy surface is withdrawn from a bath of fluid, emerging with viscous liquid entrained in the hairy texture. The drainage of the liquid trapped between the texture is modeled using a Darcy-Brinkmann like approach. The amount of fluid that is entrained depends on the viscosity of the fluid, the density of the hairs, and the withdrawal speed. Both theory and experiments show that there is an optimal hair density to maximize fluid uptake.

Finally, we investigate drop impact on hairy surfaces. By varying the speed of the drop at impact and the spacing of the hairs, we observe a variety of behaviors. For dense hairs and low impact velocity, the liquid drop sits on top of the hair, similar to a Cassie-Baxter state. For higher impact velocity, and intermediate to high density of hairs, the drops penetrate through the surface, but the hairs resist their spreading. For low hair density and high impact velocity, the drops penetrate and eject droplets upon impact.

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### The Interferometers that Detected Gravitational Waves by Jenne Driggers

Feb 22, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof.Duncan Brown/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The Advanced LIGO and Advanced Virgo detectors have revolutionized the field of gravitational wave astronomy with the direct detection of gravitational waves from the mergers of compact stellar remnants. During the observation run from November 2016 - August 2017, the interferometers greatly increased the time-volume of the universe observed as compared to the first run, detected several black hole binary mergers, and saw the first coalescence of a binary neutron star. In this talk I will discuss the status of the instruments during the latest observation run, including challenges and successes in mitigating them. I will conclude with an outlook on upgrades that are currently being implemented in preparation for our next observation run.

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### Neutron star mergers and the cosmic origin of the heavy elements by Daniel Siegel

Feb 19, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof.Duncan Brown/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The recent detection of the binary neutron star merger GW170817 by LIGO and Virgo was followed by a firework of electromagnetic counterparts across the entire electromagnetic spectrum. In particular, the ultraviolet, optical, and near-infrared emission is consistent with a kilonova that provided strong evidence for the formation of heavy elements in the merger ejecta by the rapid neutron capture process (r-process). In this talk, I will discuss the state of the art in modeling neutron star mergers from first principles, which represents a multi-physics challenge involving all four fundamental forces and petascale computing. I will present recent results from general-relativistic magnetohydrodynamic simulations and discuss possible scenarios and mass ejection mechanisms that can give rise to the observed kilonova features. In particular, I will argue that massive winds from neutrino-cooled post-merger accretion disks most likely synthesized the heavy r-process elements in GW170817. I will show how this finding (at least partially) concludes the quest for the cosmic origin of the heavy elements, which has been an enduring mystery for more than 70 years.

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### Higgs self-coupling measurement & Electroweak Phase Transition

Feb 19, 2018, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Jay Hubisz/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

I will talk about the measurement of Higgs potential and the electroweak phase transition. Higgs portal with the singlet scalar under the Standard Model gauge group with Z2 symmetry, and effective field theory approach with higher dimensional operator will be shown as an example to show that the correlation between the Higgs trilinear coupling and the quartic coupling will be useful for differentiating various underlying New Physics scenarios and discuss its prospect for the future colliders.

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### Muon/pion separation using Convolutional Neural Networks(CNNs) for the MicroBooNE charged current inclusive cross section measurement by Jessica Esquivel

Feb 16, 2018, 2:00 PM-3:00 PM

Room: 202 Physics Bldg.

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### The Search for Gravitational Waves by Alex Nitz

Feb 15, 2018, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof.Duncan Brown/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The LIGO and Virgo detectors have now observed gravitational waves from both the mergers of binary black holes and neutron stars. We’ll discuss how these discoveries were made, touch upon what we can learn from them, and look into what the future of searching for gravitational waves from binary mergers may look like.

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### Modelling epithelial cell sheets as active matter by Silke Henkes

Dec 15, 2017, 11:00 AM-12:00 PM

Rooms 202/204

Contact: David Yllanes, dyllanes@syr.edu | Host: M. Cristina Marchetti, mcmarche@syr.edu

Epithelial cell sheets are an important group of tissues that line the gut, the lungs, and cover the eye. Related tissues also form the germ layers during and after gastrulation during embryo development. Understanding their mechanics and dynamics is therefore paramount.I will give an overview of two recent approaches: First, I will discuss the results that can be obtained using extremely simple, particle based models of epithelial cell sheets. This includes the result that any amount of division fluidised a tissue at long time scales, and the existence of a universal velocity correlation function with long-range correlations. Second, SAMoS is a toolbox for active vertex model simulations, which includes the self-propelled Voronoi model, cell division and apoptosis, cell sheet boundaries, and different types of alignment. I will showcase its capabilities, but also the limitations of the approach.

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### Electromechanical Quantum Simulators by Francesco Tacchino

Dec 12, 2017, 3:00 PM-4:30 PM

202 Physics Bldg.

Host: Prof. Matt LaHaye / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Quantum simulators are one of the most appealing applications of a quantum computer. In this talk, I will describe a recent theoretical proposal [1] of a universal, scalable, and integrated digital quantum simulator in which the quantum information processing is carried out by tunable nano-electromechanical qubits within a superconducting microwave circuit. Very high operationaldelity can e achieved in a minimal architecture where qubits are encoded in the anharmonic vibrational modes of mechanical nanoresonators, whose eective coupling is mediated by virtual uctuations of an intermediate superconducting art cial atom. The explicit digital quantum simulation of the spin S = 1 tunnelling Hamiltonian and of transverseeld Ising model will be described as paradigmatic examples, displaying very large theoreticaldelities with realistic model parameters. The talk is divided in three parts. In therst one, I will summarize the basic concepts about quantum simulators, describe existing and proposed platforms for quantum computing and present some simple examples. In the second part, I will discuss the properties of quantum electromechanichal devices and some of the most interesting recent achievements in theeld. Finally, the last part of the talk will be dedicated to an extensive description of the proposed quantum electromechanical simulator.

[1] F. Tacchino, A. Chiesa, M. D. LaHaye, S. Carretta and D. Gerace, Electromechanical Quantum Simulators, arXiv:1711.000511

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### A Precision Test of Quantum Mechanics- Our Universe!

Dec 11, 2017, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The most impressive, but also surprising, prediction of Inflation is that the large scale structure of our Universe arises from quantum fluctuations at extremely small scales.  In order to test the sensitivity of the relationship between the very large and the very small we considered a non-linear version of Quantum Mechanics.  Cosmological data constrain the nonlinear parameter to be less than 10^-30 eV.  This is more stringent than bounds from laboratory tests of nonlinearity in Quantum Mechanics by many orders of magnitude.

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### Fermion-bag approach to interacting Hamiltonian lattice fermions

Dec 8, 2017, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Hamiltonian lattice field theories provide an alternate approach for studying traditional Lagrangian lattice field theories in the strongly interacting regime. An important advantage for fermionic field theories is that they can help in reducing the fermion doubling problem while preserving more symmetries.  Recent research shows that new sign problems are also solvable within this approach. These formulations are commonly used in condensed matter physics using auxiliary field Monte Carlo methods. In this talk we show how we can extend the ideas of fermion bags to the Hamiltonian formulation and accelerate the traditional methods. Using our new approach we can compute the critical exponents of the 2+1d Gross-Neveu model with Nf=1 Dirac fermions, which was impossible so far in Lagrangian lattice field theory.  Our results are based on calculations involving some of the biggest lattices in the field so far.

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### Annual Physics Department Holiday Party

Dec 7, 2017, 5:00 PM-8:00 PM

Inn Complete

Organizer: Yudaisy Salomon Sargenton, 315-443-5960

Join us for this year’s, Holiday Party! A night, filled with good food, friends and merriment!

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### The Gauss Law : A Tale

Dec 4, 2017, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The Gauss law plays a basic role in gauge theories, enforcing gauge invariance and creating edge states and superselection sectors.  This talk surveys these aspects of the Gauss law in QED, QCD and nonlinear G/H models.  It is argued that nonabelian superselection rules are spontaneously broken. That is the case with SU (3) of color which is spontaneously broken to U(1) x U(1).  Nonlinear G/H models are reformulated as gauge theories and the existence of edge states and superselection sectors in these models is established.

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### Windows for Light Charged Particles

Nov 27, 2017, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Jay Hubisz/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

There is a well-known bound from LEP that says charged fermions should have masses greater than 100 GeV. In this talk, I will revisit this bound in detail and describe the caveats involved. LHC constraints will be presented and shown to provide stronger limits, in some cases, than those from LEP. Despite both LEP and LHC limits, I will demonstrate that models exist with charged fermions as light as 70 GeV.

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### Mechanical Properties of Beta-Solenoid Proteins Using Molecular Dynamics Simulations by Amanda Parker

Nov 17, 2017, 11:00 AM-12:00 PM

Rooms 202/204

Contact: David Yllanes, dyllanes@syr.edu | Host: M. Cristina Marchetti, mcmarche@syr.edu

Beta-solenoid proteins show promise in bottom-up engineering applications due to their nano-scale size, functionalizability, stability in extreme environments, and ability to self-assemble into supramolecular structures. The potential uses of these structures depend on the mechanical properties of the building blocks-- the beta-solenoid monomers. Therefore, by understanding the proteins' mechanical strengths, we can more efficiently design them for specific functions. I will present a study of the mechanical properties of seven beta-solenoid proteins. In this study, I use GROMACS molecular dynamics software to produce force- and torque-displacement data, implement umbrella sampling of bending and twisting trajectories, produce potentials of mean force (PMFs), extract effective spring constants, and calculate rigidity, Young's modulus, and ultimate tensile strength (UTS), for two bending and two twisting directions for each protein. In addition to the results and analysis of the methods, I will propose attributes that might contribute to increased mechanical strength, and compare some results to those from experiment. I will also introduce my current work on the self-assembly of these beta-solenoid monomers, in which I conduct molecular dynamics simulations of aggregation using a structure-based, all-atom potential model.

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### Superfluid 3He, Its time again! by Dr. Jeevak Parpia

Nov 16, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Meghan Lentz / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Superfluid 3He is unlike any other liquid. It supports no natural impurities, yet can be infused with disorder that is uniquely controllable. When confined in regular geometries or when suitable disorder is introduced, new phases can emerge. I will present an overview of the research in this area, and highlight new approaches underway at Cornell and elsewhere.

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### CAE Tier I Teaching Excellence Workshop for Current and Future Astronomy and Space Science Instructors

Nov 11, 2017, 8:00 AM-5:30 PM

and Nov 12, 2017 at 8:00 AM - 5:30 PM

Stolkin Auditorium and Room 202/204 Physics Bldg.

Host: Peter Saulson. Contact: 315-443-3901

“Are you a current or future instructor teaching Astronomy, Space Science, Physics, or Geoscience? Would you like your classroom to actively engage your students in discourse about the big ideas of your class; how evidence is used to understand the universe; and the role of science in society? We invite you to come to our CAE Teaching Excellence Workshop. Spend time with your colleagues and become an effective implementer of active-learning instructional strategies.”

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### The physics of high-density crowds by Arianna Bottinelli

Nov 10, 2017, 11:00 AM-12:00 PM

Room: 202 Physics Bldg.

Host: Prof. Cristina Marchetti / Contact: Yudaisy Salomón Sargentón, 315-443-5960

During mass events such as concerts, parades, sporting events, and pilgrimages, crowd density can become extremely high, causing the emergence of potentially deadly collective motions such as “crowd turbolence” and density waves. Additionally, conventional information
transfer and communication processes appear to break down, preventing the information about dangerous situations to spread, and counteractions to be immediately taken. Taking inspiration from the physics of jammed granular materials, we were able to identify Goldstone modes, soft spots, and stochastic resonance, as the preferential mechanisms for dangerous emergent collective motions in crowds. However, understanding the coupling between information transfer and movement in the extreme case presented by high-density crowds is still an open question, and, likely, a fundamental step in understanding the dangers arising at mass gatherings.

In my talk, I will present the main goals we achieved in understanding the physical mechanisms underlying collective motions in crowds. I will then describe our current work, which focuses on extending these techniques to real crowds to obtain predictive tools for crowd safety. Finally, I will show some preliminary result on how traditional models of information dynamics can be spatially embedded to analyze the breakdown of information transfer in high-density scenarios, and its relationship with collective motion.

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### Searching for physics beyond the Standard Model at the LHCb experiment by Mike Williams

Nov 9, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Contact: Yudaisy Salomon Sargenton, 315-443-5960

The LHCb experiment at the Large Hadron Collider (LHC) at CERN has been the world's premier laboratory for studying processes in which the quark types (or flavors) change since 2011. Such processes are highly sensitive to quantum-mechanical contributions from as-yet-unknown particles, e.g. supersymmetric particles, even those that are too massive to produce at the LHC. I will discuss the status of these searches, including some intriguing anomalies. I will also present searches for the proposed dark matter analogs of the photon and the Higgs boson. Planned future upgrades and the resulting physics prospects will also be discussed, including our plans to process the full 5 terabytes per second of LHCb data in real time in the next LHC run.

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### Holographic dualities in non-perturbative 3D gravity : from spin chains to BMS characters

Nov 6, 2017, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Judah Unmuth- Yockey, Contact: Yudaisy Salomon Sargenton, 315-443-3901

To deepen our understanding of holographic dualities from a non-perturbative quantum gravity perspective we will study the Ponzano Regge partition function for a twisted solid torus. Our aim is to compare the results obtained within this non-perturbative approach to three-dimensional quantum gravity with the previous perturbative calculations of this partition function.  After reviewing shortly the necessary background I will explain how choosing different boundary states leads to different holographically dual theories, that often can be mapped to statistical models —  but with a twist.  In the limit case of a large, but finely discretized, boundary we find a dependence on the Dehn twist angle characteristic for the BMS3 character.  This connection can be strengthened by choosing coherent boundary states which allow for a one—loop evaluation of the (boundary theory) partition function. This recovers (with corrections due to non-classical bulk geometries arising from additional saddle points)  the results obtained previously by Barnich et al in the continuum via perturbative quantum General Relativity, and can be related to a character of the BMS3 group.

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### Cooperativity of driven probes in (un)confined colloidal baths by Vincent Démery

Nov 6, 2017, 1:00 PM-2:00 PM

Room 233

Contact: David Yllanes, dyllanes@syr.edu | Host: Joseph Paulsen, jdpaulse@syr.edu

When several probes are driven through a colloidal bath, for example if charged colloids are submitted to an external field in a bath of neutral colloids, they exhibit a cooperative behavior. This means that the external driving induces non-trivial effective interactions between the particles. Here, I will present recent theoretical results on these effects in two situations. In the first, the particles are free to move along the external field but also in the transverse direction, and the driven particles form lanes when the field is applied. I will discuss the properties of these lanes. In the second situation, the particles are confined to a narrow channel so that they cannot pass each other. I will show that the driven particles may bind or unbind, with strong consequences on their mobility.

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Nov 4, 2017, 8:00 PM-6:00 PM

TBD

Host: Prof. Jack Laiho jwlaiho@syr.edu

We are pleased to announce the tenth annual Undergraduate Research Day (URD) at Syracuse University.  This year’s meeting will be held on Saturday, November 4, 2017. In recent years, more than 100 students from 16 colleges and universities have participated in URD. The meeting gives undergraduates a chance to present their own research (via talks or posters) and meet with other students and professors from New York area universities and beyond.  All students are encouraged to give a talk! Click here to find out more about this event.

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### Swimming dynamics of a viscoelastic micro-swimmer by Kari Dalnoki-Veress

Nov 3, 2017, 11:00 AM-12:00 PM

Room: 202 Physics Bldg.

Host: Prof. Joseph Paulsen/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Undulatory locomotion is utilized by crawlers and swimmers, such as snakes and sperm, at length scales ranging more than seven orders of magnitude. This form of locomotion is known to be effective in various media, such as in and on the surfaces of water, soil, and agar. C. elegans is a tiny nematode: a worm that serves as a model for undulatory micro-swimming. At small length scales relevant to this worm, swimming is qualitatively different from macroscopic locomotion because the swimmers can be considered to have no inertia. I will present our studies of both the material properties as well as the dynamics of swimming using the deflection of a force-calibrated micropipette and high-speed imaging.

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### Soft Materials at surfaces and interfaces: Elastocapillarity by Kari Dalnoki-Veress

Nov 2, 2017, 3:30 PM-5:00 PM

202 Physics Bldg

Host: Prof. Joseph Paulsen/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

The physics of soft materials is distinct from hard matter as the weaker intermolecular bonds can result in a large response to external stresses. In recent years, there has been a significant interest in understanding the interaction between a liquid’s surface tension and a solid’s elasticity: elastocapillarity. In particular, liquids can generate significant deformations of highly compliant materials. These elastocapillary interactions are highly relevant in a wide variety of systems including capillary origami and folding, soft tissues, wetting of fibers and hair, and micropatterning of soft surfaces. In this talk I will summarize our recent work on the capillary interactions of liquid droplets with elastic surfaces.

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### Probing Dark Showers at LHCb

Oct 27, 2017, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Jay Hubisz/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Dark shower is a generic feature of the Hidden Valley model, which produces bound states with a high multiplicity, low masses, and long lifetimes. The showering process can arise, for example, in Neutral Naturalness models, or in dark matter scenarios that explain the possible signal of gamma-ray excess. A collider search of such signals requires good vertex resolution, low energy threshold, as well as a good particle id to veto the background. I will explain why the LHCb experiment has a great potential in seeing dark showers and compare the estimated sensitivity to that of the future ATLAS/CMS searches.

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### Flocking through a Quantum Analogy by Benjamín Loewe

Oct 27, 2017, 11:00 AM-12:00 PM

Room 208

Contact: David Yllanes, dyllanes@syr.edu

Systems composed of strongly interacting self-propelled particles can form a spontaneously flowing polar active fluid. The study of the connection between the microscopic dynamics of a single such particle and the macroscopic dynamics of the fluid can yield insights into experimentally realizable active flows, but this connection is well understood in only a few select cases. We introduce a model of self-propelled particles based on an analogy with the motion of electrons that have strong spin-orbit coupling. We find that, within our model, self-propelled particles are subject to an analog of the Heisenberg uncertainty principle that relates translational and rotational noise. Furthermore, by coarse-graining this microscopic model, we establish expressions for the coefficients of the Toner-Tu equations—the ydrodynamic equations that describe an active fluid composed of these “active spins.” The connection between self-propelled particles and quantum spins may help realize exotic phases of matter using active fluids via analogies with systems composed of strongly correlated electrons

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### Unveiling the first black holes by Dr. Priyamvada Natarajan

Oct 27, 2017, 10:15 AM-11:15 AM

Room: 202/204 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Prof Priyamvada Natarajan, this year's Wali lecturer in Science and Humanities, has generously agreed to give a additional seminar this Friday at 10:15 am in Physics (rm 202/4) Prof. Natarajan is a theoretical astrophysicist whose research interests cover black hole formation and growth, dark matter and gravitational lensing. She is also a member of the Science team for LISA - an upcoming space based gravitational wave observatory. Prof Natarajan received her PhD from the Institute of Astronomy at the University of Cambridge UK and is now a Professor at Yale.

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### The Kameshwar C. Wali Lecture in the Sciences and Humanities: "Mapping the Heavens: how radical ideas have transformed our cosmic view" by Dr. Priyamvada Natarajan

Oct 26, 2017, 4:00 PM-6:00 PM

Shemin Auditorium, Shaffer Art Building

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

From time immemorial humans have been charting the night sky and trying to make sense of it and contemplating their place in the cosmos. I will recount the evolution of celestial map-making and show how maps literally track our ever evolving cosmic view. Tracing our understanding of the universe, its contents and its evolution - in this Wali lecture, I will talk about recent developments in our understanding of two invisible entities: dark matter and black holes.

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### Bootstrapping the Stress-Energy Tensor

Oct 20, 2017, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Judah Unmuth-Yockey/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

I will discuss recent progress at extending the conformal bootstrap to 4-point functions containing the stress-energy tensor. This progress includes deriving analytical sum rules for the coefficients in stress-tensor 2-point and 3-point functions, and producing numerical bounds on these coefficients in 3D CFTs for various gaps in the spectrum. In the latter analysis we obtain the first determination of the stress-tensor 3-point function in the critical 3D Ising model.

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### Fire! Fire! (Einstein’s) Hair on Fire! The Equivalence Principle and Quantum Mechanics; Are They Compatible? by Carl Rosenzweig

Oct 19, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Contact: Yudaisy Salomon Sargenton, 315-443-5960

The Equivalence Principle is one of the physical foundations of General Relativity. Quantum Mechanics is the most successful and pervasive theory in physics. Black Holes are the setting for gedanken experiments exploring the relationship between these two pillars of modern physics.  In recent years Black Hole thought experiments suggested the existence of a firewall surrounding Black Holes. This ring of fire would fry to a crisp any physicist trying to validate the equivalence principle.  Unless Quantum Mechanics was wrong….. or something else ????

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### Tensor formulations for spin and gauge models on the lattice

Oct 16, 2017, 2:00 PM-3:00 PM

233 Physics Bldg.

Contact: Yudaisy Salomón Sargentón, 315-443-5960

I will introduce tensor formulations for spin and gauge models on the lattice, using methods from usual duality transformations.  This formulation of models changes the degrees of freedom to be

integer fields on the interaction surfaces of the original model.  I will also discuss some exact blocking methods with this formulation, as well as some approximate blocking methods, and some applications where this formulation has been advantagous.

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### Confining colloids: From dynamic artificial cells to luminescent nanodiamond sensors - by Viva Horowitz

Oct 13, 2017, 11:00 AM-12:00 PM

Rooms 202/204

Host: Lisa Manning | Contact: David Yllanes, dyllanes@syr.edu

Watching nano- and microscale particles in confined environments can reveal new physics, whether we create a dynamic system that mimics cellular motion or use the quantum spin of nanodiamonds to explore a magnetic environment. In the first part of this talk, we’ll explore the possibilities of using self-propelled particles to create a super-diffusive system that beats Brownian motion, much like the interior of cells. We’ll discuss how to investigate the motion of these particles using holography and other optical techniques, and see how these particles can be encapsulated in lipid vesicles or in droplets. The dynamics and transport processes of this artificial cytoplasm may prove necessary to sustain gene expression, growth, and reproduction in future artificial cells. In the second part, we’ll explore how nitrogen-vacancy color centers embedded in nanoparticle diamonds have electronic quantum spin states that are sensitive to magnetic fields via electron spin resonance. When we pick up these nanodiamond probes using optical tweezers, we can measure and map the magnetic environment despite the motion and random orientation of nanodiamonds levitated by the laser beam. However, challenges remain: these spin states are sensitive to impurities in the diamond crystal and surroundings. We need to find the best diamond particles for spin-based magnetic, electric, and thermal sensing in fluidic environments and biophysical systems. Toward this end, we are building a microfluidic device to sort nanodiamonds according to their optical properties.

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### Eye patches: the evolution of novel soft matter by Alison Sweeney

Oct 12, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Edward Lipson / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Life on Earth constitutes the most sophisticated iterations in the known universe of what physicists classify as soft matter.  Research in my group focuses on learning the physical rules of soft matter self-assembly phenomena via the evolutionary processes by which they arose over Earth’s history.  In this view of life as soft matter, evolution, with its own formal rules and algorithms, governs the appearance and diversification of novel forms of soft matter.  The field of soft matter was until very recently restricted to analytical consideration of simpler systems like isotropically interacting colloids and cross-linked polymers such as rubber. Our approach allows us to understand soft materials in a nuanced manner that would be inaccessible from more top-down analytical approaches.  In this talk, I will present the most detailed test case of this perspective to date: the evolutionary appearance of spherical, gradient-index lenses in squids.  This complex optical material, first described in theory by Maxwell in 1854, emerges from 5-nm spheroidal proteins via patchy colloidal physics.  The lens requires stable, transparent materials throughout the span of packing fractions (from near zero to near one); accordingly, the lens proteins exploit the entire patchy colloidal phase space, and our work is the first demonstration of many of these colloidal organizations in nature.  The self-assembling squid proteins exhibit structural features that have also been predicted by self-assembly theories but not yet realized in experiments, such that the evolved system may provide helpful insight to engineers designing systems at similar lengthscales.  Conceptually related projects such as the structure and function of quasi-ordered optics for camouflage of midwater squid eyes will also be discussed.

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### Loop equations and bootstrap methods in lattice gauge theory by Luis Martin Kruczenski

Oct 9, 2017, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

In principle, the loop equation allows, especially in the large-N limit, the formulation of a gauge theory purely in terms of Wilson loops. This is particularly so in lattice gauge theories where there is a countable number of loops. In this talk we argue that the loop equation does not uniquely determine the Wilson loops unless it is supplemented by a certain positivity condition. Imposing that a certain matrix built out of expectation values of Wilson loops is positive definite gives a well defined problem that can be approached using semi-definite programming, a well-developed numerical technique. Further, we discuss a certain entropy associated with this matrix and other related developments.

Based on arXiv:1612.08140  and work in progress.

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### The Physics of Cancer Lecture by Prof. M. Lisa Manning

Oct 6, 2017, 3:00 PM-4:00 PM

Room: 202/204 Physics Bldg.

As part of Orange Central events, Physics professor M. Lisa Manning, Ph.D., will discuss recent work that may help explain when and why cells are able to leave tumors. This research is generating new ideas about how to use cell mechanics and cell shape to quantify tumor invasiveness, which will help patients get the best treatments for their disease.

Event Cost: No charge

HE

### Fine-Tuning Constraints on Stellar Operations by Prof. Fred Adams

Oct 6, 2017, 12:00 PM-1:30 PM

208 Physics Bldg.

Host: Prof. Scott Watson / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Motivated by the possible existence of other universes, with different values for the fundamental constants, this talk considers stars and stellar structure with different values for the fundamental constants of nature. Focusing on the fine structure and gravitational constants, we first enforce the following constraints: [A] long-lived stable nuclear burning stars exist, [B] planetary surfaces are hot enough to support chemistry, [C] stellar lifetimes are long enough to allow biological evolution, [D] planets are massive enough to maintain atmospheres, [E] planets are small enough to remain non-degenerate, [F] planets are massive enough to support complex biospheres, [G] planets are less massive than stars, and [H] stars are less massive than galaxies. The parameter space that satisfies these constraints is relatively large:

viable universes can exist when the structure constants vary by several orders of magnitude. Next we consider a number of other fine-tuning issues, including the triple alpha fine-tuning problem for carbon production, nucleosynthesis in universes without stable deuterium, and structure formation in universes with varying amplitudes for the primordial density fluctuations.

In all of these scenarios, the basic parameters of physics and cosmology can vary over wide ranges and still allow the universe to operate.

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### Quantum Simulation of Quantum Chemistry by Peter Love

Oct 5, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Britton Plourde/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Quantum simulation proposes to use future quantum computers to calculate properties of quantum systems. In the context of chemistry, the target is the electronic structure problem: determination of the electronic energy given the nuclear coordinates of a molecule. Since 2006 we have been studying quantum approaches to quantum chemical problems, and such approaches must face the challenges of high, but fixed, precision requirements, and fermion antisymmetry. I will describe several algorithmic developments in this area including improvements upon the  Jordan Wigner transformation, alternatives to phase estimation, adiabatic quantum computing approaches to the electronic structure problem, methods based on sparse Hamiltonian simulation techniques and the potential for experiments realizing these algorithms in the near future.

HE

### The QCD equation of state at finite temperature and density

Oct 2, 2017, 2:00 PM-3:00 PM

Room: 202 Physics Bldg.

Host: Judah Unmuth- Yockey, Contact: Yudaisy Salomon Sargenton, 315-443-3901

The low-energy phase of the theory of strong interactions, Quantum Chromodynamics (QCD), features a remarkable property of confinement - the spectrum contains composite, color-neutral states, while states with non-zero color charge are not observed. At high temperatures and/or densities the strongly interacting matter undergoes a transition into the deconfined phase called Quark-Gluon Plasma (QGP). The properties of QGP are being studied experimentally at the Relativistic Heavy-Ion Collider (RHIC) at BNL and the Large Hadron Collider (LHC) at CERN. On the energy scales accessible to the experiments the theory is still strongly coupled and lattice gauge theory provides a non-perturbative approach for solving it with stochastic methods. The equation of state of QGP is an important input into phenomenological modeling of the relativistic heavy-ion collisions, required for interpretation of the experimental results. I review ab initio lattice calculations of the equation of state at finite temperature and density, the methodology and challenges involved and present some recent results.

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### TBD by Chandraleckha Singh and Genaro Zavala

Sep 29, 2017, 11:00 AM-12:00 PM

Room: 202/204 Physics Bldg.

Organizer: Samuel Sampere, 315-443-5999, smsamper@syr.edu

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### 6th Annual Regional AAPT Meeting

Sep 29, 2017, 7:00 AM-9:00 PM

Syracuse University Department of Physics

Organizer: Samuel Sampere, 315-443-5999, smsamper@syr.edu

NJAAPT
AAPT-NEW ENGLAND

FRIDAY

4:00 – 6:00 REGISTRATION
6:30 – 8:30 COCKTAILS AND DINNER IN HEROY LOBBY ($20) PLENARY - BETH CUNNINGHAM EXECUTIVE OFFICER AAPT 8:45 – 9:45 DEMO SHOW STOLKIN AUDITORIUM (PHYSICS BUILDING) 8:45 ~ 9:30 SATURDAY 7:30 – 8:15 REGISTRATION 8:30 – 8:50 BRAD GEARHART – SHADOWGRAMS USING YOUR IPAD 8:50 -9:10 ANNE HUNTRESS – PRINTING WITH 3D PENS 9:15 – 9:45 INVITED TALK #1 (CHANDRALEKHA SINGH OR GENARO ZAVALA) 9:50 – 10:20 INVITED TALK #2 – RYAN FISHER – THE LATEST LIGO NEWS 10:20 – 10:35 MORNING BREAK 10:40 – 11:10 INVITED TALK #3 - (CHANDRALEKHA SINGH OR GENARO ZAVALA) 11:10 – 11:30 QUESTIONS FOR MORNING SPEAKERS 11:30 – 1:00 LUNCH AND POSTERS WORKSHOPS 1:00 – 4:00 PTRA WORKSHOP, FUN AND ENGAGING LABS – STEVE HENNING (FEE:$30)
1:00 – 3:00 BICYCLE POWER WORKSHOP – SHAWN REEVES
1:00 – 2:00 3D PRINTING USING PENS – ANNE HUNTRESS

TALKS

1:00 – 1:30 JOSEPH RIBAUDO – HOW KILLER BLACK HOLES SAVED ASTRONOMY
1:30 – 2:00 CHARLES HOLBROW – ARISTARCHUS’S DISTANCES TO THE MOON AND SUN: MYTH, MYSTERY, OR
MISTAKE?
IMAGING

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### Probing Fundamental Physics with the Early Universe by Will Kinney

Sep 28, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Contact: Yudaisy Salomón Sargentón, 315-443-5960

The current revolution in high-precision cosmology is revealing amazing detail about the structure and evolution of the universe, and provides a unique laboratory to study questions in fundamental physics inaccessible to traditional particle physics methods using colliders such as LHC. For example, the physics responsible for cosmological inflation is likely to operate at an energy scale comparable to that of Grand Unification. Since inflation leaves behind observable relics, in particular primordial cosmological perturbations, the inflationary universe provides us with a "microscope'' of tremendous power. In the last decade, it has been realized that inflation may even enable us to probe physics at the very highest energies, where quantum gravity becomes important. The first observational signatures of string theory (or some other theory of quantum gravity) may well come from cosmology. In this colloquium, I introduce inflation as a probe of fundamental physics, and discuss current status and future prospects.

HE

### Glueball masses from SU(3) Matrix Model by Sachin Vaiyda

Sep 25, 2017, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Simon Catterall/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

We present variational estimates for the low-lying energies of a simple matrix model that approximates SU(3) Yang-Mills theory on a three-sphere of radius R. By fixing the ground state energy, we obtain the (integrated) renormalization group (RG) equation for the Yang-Mills coupling g as a function of R. This RG equation allows us to estimate the masses of other glueball states, which we find to be in excellent agreement with lattice simulations.

CM

### Emerging insights into directed assemble: taking examples from nature to design synthetic processes by Juan de Pablo (BMCE Distinguished Lecture)

Sep 22, 2017, 1:00 PM-2:00 PM

414 Bowne Hall

Contact: David Yllanes, dyllanes@syr.edu

There is considerable interest in controlling the assembly of polymeric material in order to create highly ordered materials for applications. Such materials are often trapped in metastable, nonequilibrium states, and the processes through which they assemble become an important aspect of the materials design strategy. An example is provided by di-block copolymer directed self-assembly, where a decade of work has shown that, through careful choice of process variables, it is possible to create ordered structures whose degree of perfection meets the constraints of commercial semiconductor manufacturing. As impactful as that work has been, it has focused on relatively simple materials – neutral polymers, consisting of two or at most three blocks. Furthermore, the samples that have been produced have been limited to relatively thin films, and the assembly has been carried out on ideal, two-dimensional substrates. The question that arises now is whether one can translate those achievements to polymeric materials having a richer sequence, to monomers that include charges, to three-dimensional substrates, or to active systems that are in a permanent non-equilibrium state. This presentation will review recent work from our group and others that explains how directed assembly of polymeric materials and liquid crystals can be used to create functional thin films for applications in separations, nanofabrication, sensors and photonic materials. Building on discoveries from the biophysics literature, I will then discuss how nature has evolved to direct the assembly of nucleic acids into intricate, fully three-dimensional macroscopic functional materials that are not only active, but also responsive to external cues. We will discuss how principles from polymer physics serve to explain those assemblies, and how one might design a new generation of synthetic systems that incorporate bio-inspired designs.

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### Physics Slam

Sep 21, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Organizer: Prof. Steven Blusk, Contact: Yudaisy Salomón Sargentón, 315-443-5960

This colloquium will be devoted to presentations specifically aimed at the undergraduate level. There will be 4 speakers, with the titles presented below:

•   “Particle Puzzles: Studying Neutrinos and Quarks at SU" by Prof. Mitch Soderberg
•    "The Extreme Mechanics of Thin Sheets" by Prof. Joey Paulsen
•    “Listening to the dark side of the universe” by Prof. Stefan Ballmer
•     "Building a Quantum Computer with Superconducting Circuits” by Prof. Britton Plourde

CM

### Soft, Structured, Living Materials by Jesse Silverberg

Sep 15, 2017, 11:00 AM-12:00 PM

Rooms 202/204

Host: Cristina Marchetti | Contact: David Yllanes, dyllanes@syr.edu

The central narrative of contemporary biology is that DNA encodes all relevant information for an organism’s function and form. While this genotype-to-phenotype framing is appealing for its reductionist simplicity, it has a substantial problem. Between nanometer-scale DNA and organismal-scale phenotype sits a gap of 5 to 9 orders of magnitude in length. This gap covers everything from active protein diffusion, and macromolecular self-assembly, to biopolymer networks and pattern forming mechanical instabilities. In other words, the story of how organisms get their function and form starts with genes, but rapidly transitions to the language of soft matter physics as we examine larger and longer length scales.

In this talk, I’ll address technological challenges and solutions for studying multiscale biophysics in an experimental setting. Along the way, I will discuss how cm-scale cartilage tissue achieves its remarkable mechanical properties through biopolymer self-organization, and how advances in big data and cloud computing can be leveraged for visualizing this nm-scale structure. I will continue to develop the theme of multiscale biophysics in the context of cell-cell fusion, a remarkably common yet mysterious processes in which individual cells fuse together to increase their size ~1,000-fold while decreasing metabolic costs by ~75%. I will also briefly touch on current work studying embryonic morphogenesis where gradients in cell growth lead to the geometric nonlinearities driving epidermal pattern formation. The physics of phase transitions, instabilities, and networks will become reoccurring themes that appear in surprising and unexpected ways as we work to close the genotype-to-phenotype gap.

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### Lattice Quantum Gravity and Asymptotic Safety by Jack Laiho

Sep 14, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Contact: Yudaisy Salomón Sargentón, 315-443-5960

We discuss the approach of lattice quantum gravity to formulating a quantum theory of gravity and how this fits into Weinberg's asymptotic safety scenario.  We present results that lattice gravity might provide a sensible definition of quantum gravity that resolves some of the long-standing problems with formulating such a theory.

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### Physics Department Fall Picnic

Sep 10, 2017, 11:00 AM-3:00 PM

Green Lakes’ Reserve Shelter

Contact: Yudaisy Salomón Sargentón, 315-443-5960

Please join us on Sunday, September 10th, 2017 for the Physics Department Fall Picnic at Green Lakes’ Reserve Shelter. There will be food, there will be games, there will be fun!

*Please note that cleanup is starts at 3 pm. Guests are welcome to stay longer if they so wish. Note that this it is a 'carry in carry out park.'

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### APS Bridge Program: Changing the Face of Physics Graduate Education by Theodore Hodapp

Sep 7, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Host: Prof. Gianfranco Vidali / Contact: Yudaisy Salomón Sargentón, 315-443-5960

In nearly every science, math, and engineering field there is a significant falloff in participation by underrepresented minority (URM) students who fail to make the transition between undergraduate and graduate studies.  The American Physical Society (APS) has realized that a professional society can erase this gap by acting as a national recruiter of URM physics students and connecting these individuals with graduate programs that are eager to a) attract motivated students to their program, b) increase domestic student participation, and c) improve the diversity of their program.  Now in its fifth year the APS has placed enough students into graduate programs nationwide to eliminate this achievement gap.  The program has low costs, is popular among graduate programs, and has inspired other departments to adopt practices that improve graduate admissions and student retention. This presentation will review project activities, present data that demonstrate effectiveness, discuss future actions, and review related efforts that inform and support activities that increase diversity within physics.

This material is based upon work supported in part by the National Science Foundation under Grant No. (NSF-1143070).

CM

### Engineering Pathways Across Biological Barriers by Shikha Nangia (BMCE Seminar)

Sep 1, 2017, 1:00 PM-2:00 PM

414 Bowne Hall

Contact: David Yllanes, dyllanes@syr.edu

The process of engineering pathways across biological barriers is entering a new era with the rapid advancement of computational resources. My research group focuses on developing multiscale simulation methods to elucidate the interfacial phenomena associated with biological barriers that play a role in life-threatening diseases such as Alzheimer’s disease, cancer, and chronic infections. The goal is to influence the experimentally dominated research field by providing mechanistic, structural, and molecular insights into the barrier functions that were computationally unattainable prior to our work. In past five years, we have made breakthroughs in each of three research domains—elucidated the molecular architecture of the blood-brain barrier and developed strategies to enhance the barrier’s permeability for treatment of the neurodegenerative diseases; developed telodendrimer based nanocarriers for efficient delivery of approved anticancer drugs for treatment of solid tumors; and designed an online computational platform to screen libraries of small molecules for their permeability across bacterial membranes and determine their use as antibiotics for treatment of chronic infections. All three research domains have ties with experimental groups to ensure the validity of our research findings. In my talk, I will elaborate on our computational methods, present the key results, and provide a perspective on the long-term research goals of the group.

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### Physics Department Welcome Reception

Aug 31, 2017, 3:30 PM-4:45 PM

Room: 202/204 Physics Bldg.

Contact: Yudaisy Salomón Sargentón, 315-443-5960

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### Adventure Course and Team building activity

Aug 23, 2017, 8:30 PM-12:30 PM

The Syracuse University Outdoor Education Center and Challenge Course. 600 Skytop Road, South Campus

Contact: Patty Whitmore, 315-443-5958

The Physics Department invites all new graduate students to participate on this fun, team building activity. See the Department orientation schedule for more details.

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### Eclipse Party

Aug 21, 2017, 11:00 AM-3:00 PM

Host: Sam Sampere. Contact: Yudaisy Salomon Sargenton, 315-443-3901

There is going to be a partial solar eclipse visible from Syracuse on Monday August 21. To accentuate this celestial event and promote greater science understanding, the Physics Department will be hosting an Eclipse Party.

We will start with live streaming of the eclipse starting at 11 am in Stolkin Auditorium (located in the Physics Building). Prof. Carl Rosenzweig will give a short talk on celestial mechanics and why eclipses are not more frequently seen. Following the talk will come the actual eclipse, and we invite all attendees to join us on the quad right outside the Physics Building. We will have two telescopes focused on the sun for up close and personal viewing of this rare occasion. We will also have a limited amount of solar viewing glasses, so you can witness the event without damaging your eyes. Never look at the sun without proper eye protection, even during a partial eclipse.

West Lot and Irving Garage at available for parking at no charge for anyone wanting to come to campus to watch the eclipse on Monday

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### Annual Pancake Breakfast

Aug 21, 2017, 9:00 AM-10:00 AM

Room: 202/204 Physics Bldg.

Host: Sam Sampere. Contact: Patty Whitmore, 315-443-5958

The Physics Department is hosting the Annual Pancake Breakfast on Monday, August 21, 2017. All graduate students, faculty and staff are invited. Please come and meet our new graduate students in a fun, relaxed atmosphere. A delicious hot breakfast will be served.

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### Quarknet 2017

Aug 21, 2017, 8:00 AM-4:00 PM

8/21 Room 104N, 8/22 and 8/23 Room 208 Physics Bldg.

Host: Prof. Steven Blusk/ Contact: Yudaisy Salomón Sargentón, 315-443-5960

Ten high school teachers from local area high schools will participate in an event sponsored by the experimental high energy physics group. Teachers will be setting up a cosmic ray detector to measure and analyze the cosmic ray flux before, during and after the solar eclipse. Teachers will also engage in an activity using data from the CMS experiment at CERN, where they study decays of a massive particle called the Z0 boson. The activities will be guided by and supplemented with presentations by Profs. Blusk and Rudolph.” For details about the event, click here

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### Comprehensive exam

Aug 19, 2017, 2:00 PM-4:00 PM

Room: 202/204 Physics Bldg.

Contact: Patty Whitmore, 315-443-5958

Saturday, August 19 and Sunday, August 20;
2:00 p.m. - 4:00 p.m.
ALL INCOMING STUDENTS

Comprehensive Exam

Part I - Saturday; Part II - Sunday

There are two examinations given in August. All new graduate students must take the comprehensive examination. You may choose to attempt the qualifying examination. - email pawhitmo@syr.edu if you would like to take it. Second year students take the qualifying examination. Bot examinations have two parts: one on Saturday, one on Sunday).

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### Qualifying Exam

Aug 19, 2017, 9:00 AM-12:00 PM

Room: 202/204 Physics Bldg.

Contact: Patty Whitmore, 315-443-5958

Saturday, August 19 and Sunday, August 20;
9:00 a.m. - 12:00 p.m.

Qualifying Exam

There are two examinations given in August. All new graduate students must take the comprehensive examination. You may choose to attempt the qualifying examination. - email pawhitmo@syr.edu if you would like to take it. Second year students take the qualifying examination. Both examinations have two parts: one on Saturday, one on Sunday).

TD

### Thesis Defense by Kazage J Christophe Utuje

Jul 13, 2017, 1:30 PM-3:30 PM

202 Physics Bldg.

Advisor: Prof. Cristina Marchetti / Contact: Yudaisy Salomón Sargentón, 315-443-5960

TD

### Thesis Defense by Prashant Mishra

Jul 12, 2017, 11:30 AM-1:30 PM

202 Physics Bldg.

Advisor: Prof. Cristina Marchetti / Contact: Yudaisy Salomón Sargentón, 315-443-5960

HE

### Little Conformal Symmetry by Rachel Houtz

May 8, 2017, 2:00 PM-3:00 PM

Room: 202 Physics Bldg.

Host: Prof. Jay Hubisz / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Given the lack of conventional SUSY signals in the LHC data, a more complicated story may be required to explain weak scale physics. I will present a new class of natural models which ensure the one-loop divergences in the Higgs mass are cancelled. The top-partners that cancel the top loop are new gauge bosons, and the symmetry relation that ensures the cancellation arises at an infrared fixed point. Such a cancellation mechanism can, a la Little Higgs models, push the scale of the new physics that completely solves the hierarchy problem up to 5-10 TeV. When embedded in a supersymmetric model, the stop and gaugino masses provide the cutoffs for the loops, and the mechanism ensures a cancellation between the stop and gaugino mass dependence of the Higgs mass parameter.

CM

### Information, Computation, and Thermodynamics in Cells - by Pankaj Mehta

May 5, 2017, 11:00 AM-12:00 PM

Rooms 202/204

Host: Lisa Manning | Contact: Tyler Engstrom, taengstr@syr.edu

Cells live in complex and dynamic environments. Adapting to changing environments often requires cells to perform complex information processing, and cells have developed elaborate signaling networks to accomplish this feat. These biochemical networks are ubiquitous in biology. They range from naturally occurring biochemical networks in bacteria and higher organisms, to sophisticated synthetic cellular circuits that rewire cells to perform complex computations in response to specific inputs. The tremendous advances in our ability to understand and manipulate cellular information processing networks raise fundamental questions about the physics of information processing in living systems. I will discuss recent work in this direction trying to understand the fundamental constraints placed by (nonequilibrium) thermodynamics on the ability of cellular circuits to process information and perform computations and discuss the implications of our results for the emerging field of synthetic biology.

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### The wool over our eyes: how scientists think they and their institutions are objective, but aren’t by Brian Nord

Apr 28, 2017, 2:00 PM-3:00 PM

Room: 202 Physics Bldg.

CM

### Morphogenesis of the first branchial arch - by Sevan Hopyan

Apr 28, 2017, 11:00 AM-12:00 PM

Rooms 202/204

Host: Cristina Marchetti | Contact: Tyler Engstrom, taengstr@syr.edu

The nuanced shapes of emerging organ primordia are intimately related to pattern formation and postnatal function, although the mechanisms that shape a volume of tissue in the embryo are not well understood.  The mandibular portion of the first branchial arch is composed of a volume of mesenchyme surrounded by a single cell layer epithelium.  Here we ask how this structure acquires a proximally narrow and distally bulbous shape during outgrowth.  Using the mouse embryo as a model system, we measured cell cycle times, as well as Young’s modulus and viscosity using atomic force microscopy.  Incorporating these data into a finite element model, we show that the spatial variation of cell division and physical properties is insufficient to explain mandibular arch shape.  By combining time lapse light sheet microscopy of intact mouse embryos with custom cell tracking, we observed that volumetric convergent extension due to the intercalation of mesenchymal cells in 3D likely underlies the narrow and elongate shape of the mandiublar arch mid-portion.  By knocking-in a transgenic FRET-based vinculin tension sensor into the mouse genome, we show that relatively high amplitude cortical force oscillations correlate with mesenchymal cell intercalations, and are oriented by polarised actomyosin.  Evidence from loss and gain of function studies suggest that Wnt5a acts as a directional cue to regulate both the orientation and oscillation amplitude of cell cortices.

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### Our Warped Universe: Strong Lensing and Deep Machine Learning in Modern Cosmology Surveys by Brian Nord

Apr 27, 2017, 3:30 PM-5:00 PM

202 Physics Bldg.

Refreshments at 3:30 pm and the talk starting at 3:45 pm

Host: Prof. Scott Watson / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Current and future galaxy surveys will provide data sets unprecedented in size and precision with which to measure dark energy, dark matter and the early universe through probes like strong gravitational lensing. I will discuss our progress in the Dark Energy Survey (DES) to detect, spectroscopically confirm, and characterize lenses. Then, we’ll look at the oncoming era of astronomically big data. Specifically, we’ll discuss techniques, results, and the potential of deep machine learning in its application to cosmology.

TD

### Early universe cosmology as a probe of fundamental physics by Ogan Ozsoy

Apr 26, 2017, 2:30 PM-4:00 PM

Room: 202 Physics Bldg.

Advisor: Prof. Scott Watson / Contact: Yudaisy Salomón Sargentón, 315-443-5960

The features of the universe we probe today are a reflection of the underlying physics at high energies and is a powerful motivation that drives theoretical research in modern cosmology. Precision observations of the Cosmic Microwave Background Radiation and the Large Scale Structure in the universe have already taught us a great deal about what may have occurred at high energies and early times in the universe’s history. In particular, the inflationary paradigm and the existence of cold dark matter stands as the two main pillars of standard model of cosmology (LCDM) which constitutes much of our modern understanding of the world we see today from a cosmological perspective. Despite the successful reconciliation of these theoretical ideas with precision data, we are far from a complete understanding of the particle physics nature of dark matter, inflationary dynamics and how the post-inflationary evolution proceeds. In this talk, I will present several theoretical ideas motivated by bottom-up and top-down constructions in field theory and explore their observational consequences in the hope of shedding some light on these phenomena.

TD

### Defects and Rearrangements in Disordered Solids by Sven Wijtmans

Apr 26, 2017, 9:30 AM-11:30 AM

Room: 202 Physics Bldg.

Advisor: Prof. Lisa Manning / Contact: Yudaisy Salomón Sargentón, 315-443-5960

In this thesis, I will investigate the properties of disordered materials under strain.  Disordered materials encompass a large variety of materials, including glasses, polymers, and gels.  There is currently no constitutive equation that describes these materials. Given the prevalence and usefulness of these materials, we derive tools to aid our understand of them.

We develop a new method to isolate localized defects from extended vibrational modes in disordered solids.  This method augments particle interactions with an artificial potential that acts as a high-pass filter: it preserves small-scale structures while pushing extended vibrational modes to higher frequencies.  The low-frequency modes that remain are bare" defects; they are exponentially localized without the quadrupolar tails associated with elastic interactions. We demonstrate that these localized excitations are excellent predictors of plastic rearrangements in the solid. We characterize several of the properties of these defects that appear in mesoscopic theory of plasticity, including their distribution of energy barriers, number density, and size, which is a first step in testing and revising continuum models for plasticity in disordered solids.

We study rearrangement types in disordered packings of particles with a harmonic potential at a range of packing fractions above jamming.  We develop a generalizable procedure that classifies events by stress drop, energy drop, and reversibility under two protocols.  We find a large population of contact change events that have no associated stress drop. Reversible events become more common at high pressures above a packing fraction of $\phi=0.865$, at which point line reversible events are more common than loop reversible events. At low pressures, irreversible events are associated with spatially extended events, while at high pressures reversible events are much more spatially localized.

HE

### TBD by Prateek Agrawal

Apr 24, 2017, 2:00 PM-3:00 PM

202 Physics Bldg.

Host: Prof. Jay Hubisz / Contact: Yudaisy Salomón Sargentón, 315-443-5960

CM

### Geometry of twisted filaments - by Arshad Kudrolli

Apr 21, 2017, 11:00 AM-12:00 PM

Rooms 202/204

Host: Joseph Paulsen | Contact: Tyler Engstrom, taengstr@syr.edu

We will discuss the fundamental interplay of geometry, elasticity, and
applied stress in determining the hierarchical shapes and mechanical
response of slender elastic materials. A ribbon under a subtle
combination of tension and twist can transform into a rich variety of
shapes including helicoids, triangular folds, tubes, plectonemes,
scrolls, and self-wrapped disordered crumpled structures. The
nucleation topological defects and the growth of wrinkles will be
analyzed with a far-far-threshold approach. We will then examine the
interaction between a set of uniform fibers which are twisted starting
from a hexagonal lattice arrangement. The non-Euclidean geometry of
twisted fiber bundles are an important motif in materials ranging from
cables to textiles and tissues. The evolution of defects as a function
of twist will be examined in light of a new model of the fiber bundle
structure.

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### Reviving Creativity in Our Introductory Physics Labs by Mats Selen

Apr 20, 2017, 3:30 PM-5:00 PM

202 Physics Bldg.

Refreshments at 3:30 pm and the talk starting at 3:45 pm

Host: Prof. Gianfranco Vidali / Contact: Yudaisy Salomón Sargentón, 315-443-5960

Approaching a question without fear; coming up with an idea; designing an experiment; understanding assumptions; interpreting data and revising the idea (or the question) accordingly. Many physicists would claim they do this for a living, and most would be delighted to observe this behavior in their students, yet for a variety of reasons this is often not what we encourage in our introductory physics labs.

We have developed a portable wireless lab system with the goal of putting simple yet powerful tools in the hands of every student, and we are currently piloting a new design-based approach to our introductory physics labs based on this tool. Our students invent experiments and acquire data, both in and out of the classroom, and share their data with each other and with instructors using an integrated cloud based repository. This new approach is allowing us to shift the focus of our introductory labs toward creativity, design, sense-making, and communication. I will describe this project and present some encouraging first results.

HE

### The Turbulent Vacuum by A.P. Balachandran

Apr 14, 2017, 12:00 PM-2:00 PM

208 Physics Bldg.

Host: Prof. Simon Catterall / Contact: Yudaisy Salomón Sargentón, 315-443-5960

*The following work is jointly done with M.Asorey, F.Lizzi and G.Marmo.

The vacuum state in relativistic quantum field theory is often pictured as devoid of striking properties, as vacuous. But instead the following are true :

1) Atoms or measuring apparatus inserted at space-like distances in vacuum should exhibit no correlations in the above image of the vacuum. But instead if they have localised states with orthogonal wave functions, and atom 1 is in ground state and 2 in an excited state at a space-like distance, either 1 will *never *be affected by 2 via photon emission (which is absurd) or it will be *instantaneously* affected violating causality.

2) Fields in a finite region, no matter how small, acting on the vacuum can produce *any* state in the Hilbert space.

3) Invariance of the vacuum is invariance of the world. (Coleman).

4)There are * no *localised detectors ! ( Implications for a causal quantum information theory ?)

After discussions of the above, we apply them to the Rindler wedge. There we show that photon  or graviton *cannot* be confined to the wedge : there is information leakage out of the wedge (but no unitarity violation). This happens because in qed  and gravity , infrared effects break ( asymptotic ) Lorentz invariance . The above result has potential applications to black hole information paradox. The super selection rules in the two cases are charge and momentum conservation respectively.

CM

### The geometry and topology of granular matter - by Daniel Sussman

Apr 14, 2017, 11:00 AM-12:00 PM

Rooms 202/204

Host: Jen Schwarz | Contact: Tyler Engstrom, taengstr@syr.edu

The fact that granular systems are nearly always perched on the verge of mechanical instabilities lends them many surprising material properties; these properties in turn inform phenomena ranging from earthquakes to soft robotics. The jamming transition provides a useful framework for understanding granular matter as well as a wide class of soft matter systems, and computational methods are a natural candidate to study these strongly correlated many-body systems. In this talk I will discuss how the combination of computational techniques with geometrical and topological approaches – including ideas inspired by topological insulators – can teach us something new about both the jamming transition and the rich phenomena of jammed matter itself, as well as potentially lead to the creation of novel mechanical metamaterials.

C

### Massive Gravity and Time-Dependent Black Holes by Rachel Rosen

Apr 13, 2017, 3:30 PM-5:00 PM

202 Physics Bldg.

Refreshments at 3:30 pm and the talk starting at 3:45 pm

Host: Prof. Scott Watson / Contact: Yudaisy Salomón Sargentón, 315-443-5960

The predictions of General Relativity (GR) have been confirmed to a remarkable precision in a wide variety of tests.  Consistent and well-motivated modifications of GR have been notoriously difficult to obtain.  However, in recent years a compelling theory has been shown to be free of the traditional pathologies.  This is the theory of massive gravity, in which the graviton is described by a massive spin-2 particle.  In this talk I will give a brief review of recent developments in massive gravity.  I will then present new results concerning intriguing features of black holes in this theory.

S

### Why Black Holes Matter by Prof. Paul Souder

Apr 8, 2017, 9:00 AM-1:00 PM

Aurora Inn (391 Main St., Aurora) on Cayuga Lake

The intriguing and fascinating world of black holes is the subject of a lecture by nuclear physicist Paul Souder, benefitting the Southern Cayuga Planetarium and Observatory in Aurora, New York.

Souder, a professor of physics at Syracuse University, will deliver a multimedia presentation titled “Why Black Holes Matter” on Saturday, April 8, at 11 a.m. at the historic Aurora Inn (391 Main St., Aurora) on Cayuga Lake. He will provide an overview of black holes, as well as share some recent findings, including the discovery of a rare, medium-weight black hole.

The event is open to the public; however, registration is required. Tickets are $45, and include the lecture, lunch and a silent auction. To register, please call 315.685.7163, or send a check, payable to “Friends of the Southern Cayuga Planetarium,” to P.O. Box 186, Aurora NY 13026. Seating is limited; tickets also are available at the door, while supplies last. Following the lecture, attendees are entitled to a free private tour of MacKenzie-Childs, a Victorian farm that produces high-end tableware and home furnishings, and a$5 wine tasting at Bet the Farm Winery and Gourmet Market.

HE

### A Nonperturbative Regulator for Chiral Gauge Theories

Feb 22, 2016, 2:00 PM-4:00 PM

202 Physics

Host: Jay Hubisz, jhubisz@syr.edu | Contact: David Schaich, daschaich@gmail.com

I discuss a new proposal for nonperturbatively defining chiral gauge theories, something that has resisted previous attempts. The proposal is a well defined field theoretic framework that contains mirror fermions with very soft form factors, which allows them to decouple, as well as ordinary fermions with conventional couplings. The construction makes use of an extra dimension, which localizes chiral zeromodes on the boundaries, and a four dimensional gauge field extended into the bulk via classical gradient flow. After explaining the set up, I consider open questions, such as the effects of topological gauge configurations and the viability of these theories, as well as possible exotic phenomenology in the Standard Model lurking at the low energy frontier.

C

### LIGO Observation

Feb 18, 2016, 3:45 PM-5:45 PM

202/204 Physics

(refreshments 3:30pm)

Contact: Yudaisy Salomon Sargenton, yssargen@syr.edu

To follow up on the public announcement last week, the LIGO faculty tomorrow will present scientific information about the observation of gravitational waves. You are all invited tomorrow, with refreshments at 3:30 and the presentation starting at 3:45, Thursday, Feb. 18, to learn more about this discovery.

HE

### New Possibilities with Top Partial Compositeness

Feb 15, 2016, 2:00 PM-4:00 PM

202 Physics

Host: Jay Hubisz, jhubisz@syr.edu | Contact: David Schaich, daschaich@gmail.com

I will review the content of 1501.03818 and 1511.05163. Top partial compositeness is a common feature of composite Higgs models. We study the case where masses for lighter quarks are generated through a different mechanism and we discuss the impact of the experimental constraints on the model, in a specific realization with a pseudo Nambu Goldstone boson Higgs. We show that there is no need for flavor symmetries is the up sector, while in the down sector a certain degree of alignment is required. We finally comment on model building aspects, introducing new physics sector with light top partners candidates, relating their lightness to 't Hooft anomaly matching condition.

CM

### The Large-Scale Thermal Stiffening of Graphene Ribbons

Feb 12, 2016, 11:00 AM-1:00 PM

202/204 Physics

Host: Mark Bowick | Contact: Yudaisy Salomon Sargenton, yssargen@syr.edu

We use molecular dynamics to study the vibration of a thermally fluctuating 2D elastic membrane clamped at both ends. We identify the eigenmodes from peaks in the frequency domain of the time-dependent height and track the dependence of the eigen-frequency of a given mode on the bending rigidity of the membrane. We find that the effective bending rigidity tends to a constant as the bare bending rigidity vanishes, supporting theoretical arguments that the macroscopic bending rigidity of the membrane as a whole arises from a strong renormalization of the microscopic bending rigidity. Experimental realizations include two-dimensional atomically thin membranes such as graphene and molybdenum disulfide or polymerized membrane ribbons.

HE

### EFT of Large Scale Structure, Symmetries and Constraints

Feb 8, 2016, 2:00 PM-4:00 PM

202 Physics

Host: Scott Watson, gswatson@syr.edu | Contact: David Schaich, daschaich@gmail.com

I will briefly introduce EFT of large scale structure (LSS) as a systematic perturbative approach to study structure formation. I will identify the symmetries and unique features of the system which determine the structure of EFT expansion. I will show how these symmetries can be used to make non-perturbative predictions about the baryon acoustic peak in the matter correlation function. Finally, I will show how EFT allows us to get unbiased constraints on cosmological parameters such as primordial non-Gaussianity and Neutrino masses from LSS surveys.

HE

### Cosmology in Standard Einstein Gravity with Non-Standard Scalar Field Fluids

Feb 5, 2016, 12:30 PM-2:30 PM

208 Physics

Host: Scott Watson, gswatson@syr.edu, 315-443-8280

I will discuss cosmological solutions in standard Einstein gravity sourced by non-standard, non-canonical scalar field fluids. With recent experimental data from Planck, BICEP2, and the Keck Array now putting stress on the simplest inflationary models, there is a growing need for alternative early universe scenarios. Examples of such fluids include k-essence, DBI, Galileon fields, Horndeski models and the 'new oscillatory' models recently proposed by Nobel Laureate Wilczek et al. I will focus on the stability of these fluids emphasizing the common occurrence of negative kinetic energy degrees of freedom (ghosts), gradient instabilities (imaginary sound speed), superluminal propagating modes and singularities. Cosmological scenarios I will discuss include K-inflation, Galilean Genesis super-inflation, and the G-bounce model.

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Contact Information:
David Schaich, Series Director
daschaich@gmail.com
315-415-3277

C

### The Fluid Boundary - Considering Cell Membranes from a Soft Matter Perspective

Feb 4, 2016, 3:45 PM-5:45 PM

202/204 Physics

(refreshments 3:30pm)

Host: Cristina Marchetti

The plasma membrane surrounding cells is composed of lipids and proteins, and is coupled to cytoskeletal fibers and to extracellular matrix. The mixture of lipids that makes up most cell membranes is fluid, forming a liquid film. As a consequence of this fluidity, flow near a membrane can induce a sympathetic flow of lipids and membrane proteins. I will discuss experiments demonstrating this lipid mobility in immobile membranes, and show that fluid flow can be used to advect proteins within lipid bilayers, producing a local concentration gradient.

http://www.damtp.cam.ac.uk/people/a.honerkamp-smith/

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Contact Information:
yssargen@syr.edu
315-443-3901

C

### Elasto-capillarity - A New Toolkit for Directed Assembly of Advanced Materials

Jan 28, 2016, 3:45 PM-5:45 PM

202/204 Physics

(refreshments 3:30pm)

Host: Cristina Marchetti

The opportunities for guiding assembly using elastic energy stored in soft matter are wide open. The emerging scientific frontiers in this field show an exceptional promise for significant new applications. Since soft materials can be readily reconfigured, there are unplumbed opportunities to make responsive devices including smart windows for energy efficiency, and responsive optical structures. In the other hand, the trapping of colloidal objects at interfaces between immiscible fluids has proven to exhibit incredible abilities to template the arrangement of particles into rich ordered structures. These structures are controlled by lateral forces that compete with capillary forces. However, these interactions are still unexplored when particles are trapped at the interface of an ordered fluid. In this talk, I will present recent progress in understanding the mechanisms that govern interactions between particles at liquid crystal interfaces. I will report how the resulting potential induced by the interplay between elasticity and capillarity could lead to new opportunities for genuine spontaneous self-assembly and create new strategies for making new generation of advanced materials that may find relevance in many applications in the field of energy technology.

http://magharbi.wordpress.com/

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Contact Information:
yssargen@syr.edu
315-443-3901

C

### Good Defects or What Confined Liquid Crystals Can Do

Jan 21, 2016, 3:45 PM-5:45 PM

Room 202/204

(refreshments 3:30pm)

Host: Cristina Marchetti

Liquid crystals are best known for their use in displays, but their interest extends far beyond. This phase of matter, intermediate between liquid and solid, is composed by anisotropic rod-like molecules which spontaneously align in space. When the molecules cannot achieve a perfect order, they form topological defects, mathematical objects which can be used as physical objects for many purposes. I show two examples of how liquid crystal defects can inspire concepts for new materials. The first example is a bistable system, obtained by confining liquid crystals in a micron-sized cubic scaffold. The device can switch between bright and dark metastable states, thanks to the interaction of the defects with the scaffold. The second example is a self-assembled structure of liquid crystal defects that act as micro-lenses. The structure resembles an insect compound eye, able to focus objects at different distances and sensitive to the polarization of light.

Figure 1: Top panel: stable bright and dark states of a display pixel obtained by changing the topological defects. Bottom panel: self-assembled defects around a central pillar. Each defect act as a micro-lens.

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Contact Information:
yssargen@syr.edu
315-443-3901

C

### Physics of Cells - Turning Protein Networks into Active Materials

Jan 19, 2016, 3:30 PM-6:00 PM

Room 202 and 204 Physics

NOTE: Tuesday Colloquium

Yudaisy Salomon Sargenton, yssargen@syr.edu

Cells are densely packed collections of proteins. By regulating the organization and interaction of these proteins in both space and time, cells turn collections of molecules into networks with various material properties. Here I will discuss how these networks allow cells to generate force and change shape, and the approaches we use to measure their behavior. Finally I will discuss ways in which we can perturb the system using light to spatially control the activity of the component proteins. http://home.uchicago.edu/~poakes/

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Contact Information:
yssargen@syr.edu
315-443-3901

C

### Photoproduction of Scalar Mesons, and Upgrade of the CLAS Electromagnetic Calorimeter at Jefferson Lab

Jan 5, 2016, 10:30 AM-12:30 PM

202 Physics

Host: Sheldon Stone

The standard quark model makes no allowance for the existence of gluons outside hadrons; however lattice QCD calculations predict bound states of two or more gluons, called glueballs. According to lattice calculations, the lightest of these experimentally unverified particles is expected to have mass in the range of 1−1.8 GeV and JPC = 0++. Themixing of glueball states with neighbouring meson states complicates their identification. The f0(1500) is one of several candidates for the lightest glueball, whose presence in the K0 sK0 s channel was investigated in photoproduction using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. This was done by studying the reaction, γp → fJp → K0 sK0 s p → 2(π+π−)p using data from the g12 experiment. A moments analysis was performed on this data to characterize the spin properties of the resonance observed at 1.5 GeV. Results from the analysis of this data will be presented.

The g12 experiment ran with the CLAS6 detector, so named because of its capability to work with a maximum electron beam energy of 6 GeV. Jefferson Lab has since upgraded its facility to produce electron beam with double that energy. The higher beam energy means that the energy of electrons and photons impinging on the detector will be too high to be contained by the existing CLAS6 electromagnetic calorimeter (EC). Several of the experiments commissioned to be performed using CLAS12 require the accurate detection of neutral pions via their decay into two photons. At the energies of CLAS12, the calorimeter needs to have a very good position resolution in order to be able to detect these two photons and to avoid their labeling as a single photon. It was thus necessary to update the detector sub-system in order to improve its functionality at higher energies. To do this, another calorimeter, the preshower calorimeter (PCAL) is to be placed in front of the EC, the testing and construction of which will be discussed.

TD

### Thesis Defense - Vortices and Quasiparticles in Superconducting Microwave Resonators

Dec 11, 2015, 2:00 PM-4:00 PM

208 Physics

HE

### Neutral B and Bs Meson Mixing from Lattice QCD

Dec 11, 2015, 12:30 PM-2:30 PM

208 Physics

Host: Jack Laiho, jwlaiho@syr.edu, 315-443-0317

Neutral B(s) meson mixing occurs via flavor-changing neutral currents.  In the standard model of particle physics this requires quantum fluctuations, or loop diagrams, making the required interactions improbable --- opening the door for the possibility of discernible effects from new physics.  There are impressive experimental results in B(s) mixing, with the oscillation frequency between B(s) and anti-B(s) mesons measured with better than sub-percent precision.  To better leverage such experimental results in the search for new physics, hadronic contributions must be determined with improved precision.  We will discuss an ongoing, nearly complete, lattice QCD calculation of the hadronic matrix elements needed to describe mixing in and beyond the standard model.  This work is being carried out by the Fermilab Lattice and MILC collaborations on the MILC Nf=2+1 asqtad gauge field ensembles, including four lattice spacings and numerous light quark masses to permit controlled extrapolations to real-world values.

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Contact Information:
David Schaich, Series Director
daschaich@gmail.com
315-415-3277

TD

### Thesis Defense - Understanding Disordered Systems Through Numerical Simulation and Algorithm Development

Dec 10, 2015, 2:00 PM-4:00 PM

208 Physics

C

### First-Principles Determination of Hadronic Contributions to the Muon Anomalous Magnetic Moment

Dec 7, 2015, 2:00 PM-4:00 PM

202 Physics

Host: Jack Laiho, jwlaiho@syr.edu, 315-443-0317

In order to match the increased precision of the upcoming Fermilab E989 experiment, a more precise determination of hadronic contributions to the muon anomalous magnetic moment is needed.  I will present recent progress in a first-principles determination of both the hadronic vacuum polarization and the hadronic light-by-light contribution.

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Contact Information:
David Schaich, Series Director
daschaich@gmail.com
315-415-3277

CM

### DNA as a Sensor of Hg Nanoparticles

Nov 30, 2015, 11:30 AM-1:30 PM

202/204 Physics

Host: Cristina Marchetti

**NOTE: MONDAY SEMINAR**

Biomolecules can be used to provide control in organizing technologically important objects into functional nano-materials.

The interaction between biomolecules and inorganic materials is fundamental to these applications. These studies are expected to play role in the design of novel hybrid materials and new sensors for biological and non-biological objects. In our study we have utilized the DNA in two folds. Firstly we useDNA to fabricate self-assembled nanostructures of Hg. Secondly we demonstrate that the DNA can be used as a sensor of Hg nanoparticles. Mercuric nanoparticles (NP) have been fabricated within the DNA scaffold by site specific interactions. The NP get embedded within double helix and exclusively interact with the nucleic acid of DNA, having no influence on the phosphate backbone of DNA. Furthermore, conjugation of Hg NP with DNA exhibits a rectifying transport behavior, with the unreacted DNA displaying the ohmic behavior.

Formation of metal-base complexes as well as the modifications in transport (electrical) properties of DNA can be utilized as sensor of mercury contamination.

Shikha Varma homepage

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Contact Information:
shdavis@syr.edu
315-443-5960

HE

### Freeze-In Dark Matter with Displaced Signatures at Colliders

Nov 23, 2015, 2:00 PM-4:00 PM

202 Physics

Host: Jay Hubisz, jhubisz@syr.edu, 315-443-2653

Freeze-in is a general and calculable mechanism for dark matter production in the early universe. Assuming a standard cosmological history, such a framework predicts metastable particles with a lifetime generically too long to observe their decays at colliders. In this talk, I will consider alternative cosmologies with an early matter dominated epoch, and I will show how the observed abundance of dark matter is reproduced only for shorter lifetimes of the metastable particles. Famous realization for such a cosmology are moduli decays in SUSY theories and inflationary reheating. Remarkably, for a large region of the parameter space the decay lengths are in the displaced vertex range and they can be observable at present and future colliders. I will conclude with an example of DFSZ SUSY theories where this framework is realized.

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Contact Information:
David Schaich, Series Director
daschaich@gmail.com
315-415-3277

HE

### The Vector Portal at the LHC

Nov 20, 2015, 12:30 PM-2:30 PM

208 Physics

Host: Jay Hubisz, jhubisz@syr.edu, 315-443-2653

An emerging paradigm in particle physics is the possibility that new matter resides in its own sector — a Dark Sector (DS) — connected to the Standard Model via a portal. In this talk I will focus on a well-motivated example of such a scenario: the vector portal. I will discuss two distinct phases of the theory. In one, matter in the DS is a viable candidate for Dark Matter, giving rise to striking new signals at the LHC. In the other phase of the vector portal, matter in the DS can instead acquire a milli-charge under electromagnetism. I will then discuss a recent proposal to look for milli-charges at the LHC.

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Contact Information:
David Schaich, Series Director
daschaich@gmail.com
315-415-3277

CM

### TBA

Nov 20, 2015, 11:00 AM-1:00 PM

202/204 Physics

Host: Britton Plourde

Matteo Mariantoni web page

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### Inside Physical Review Letters

Nov 19, 2015, 3:45 PM-5:45 PM

202/204 Physics

Host: Lisa Manning

How do its editors determine which papers to publish in PRL? What guidelines would be helpful to you as an author and a referee? Why should you submit your work to us? How are journals in general and PRL in particular reorienting amid increasing challenges in the landscape of physics publications? I plan to address these and related issues, including a few changes we're implementing, during my presentation.

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Contact Information:
shdavis@syr.edu
315-443-5960

CM

### Emergence of Large-Scale Epithelial Mechanics from Cell-Scale Processes - Shaping a Fly Wing

Nov 13, 2015, 11:00 AM-1:00 PM

202/204 Physics

Host: Mark Bowick

Epithelia are two-dimensional cellular sheets. They are active visco-elastic materials which gain their mechanical properties from the collective behavior of a large number of cells. Nowadays, we are able to image tissues with up to 10 000 cells in vivo where the behavior of each individual cell can be followed in detail. We want to understand how large-scale tissue deformation and stresses emerge from the behavior of individual cells.

Here, we study this question in the developing Drosophila wing epithelium. We first establish a general geometrical framework that exactly decomposes large-scale tissue deformation into contributions by different kinds of cellular processes. These processes comprise cell shape changes, cell neighbor exchanges (T1 transitions), cell divisions, and cell extrusions (T2 transitions). As the key idea, we introduce a tiling of the cellular network into triangles. This allows us to define the precise contribution of each kind of cellular process to large-scale tissue deformation. Additionally, our rigorous approach reveals subtle effects of correlated cellular motion, which constitute a novel source of tissue deformation.

Based on this geometrical framework, we describe Drosophila wing mechanics using a novel continuum mechanical model. Similar to preceding models, we describe the wing epithelium as visco-elastic. However in addition to that, our observations led us to appreciate novel effects.

We found active cell rearrangements that are oriented on large scales and have an axis orthogonal to the shear stress axis. Furthermore, cell rearrangements did not respond immediately to material stresses, but were rather delayed. These findings are further underpinned using mechanical and genetic perturbations.

With our work, we contribute to an understanding of epithelial deformation and mechanics, linking it to cellular mechanical properties and cell-scale events.

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Contact Information:
shdavis@syr.edu
315-443-5960

HE

### Models and Signatures for Neutral Naturalness

Nov 9, 2015, 2:00 PM-4:00 PM

202 Physics

Host: Jay Hubisz, jhubisz@syr.edu, 315-443-2653

In the light of the null results in searches for top partners at the 8 TeV LHC, there recently has been an increased interest in models with color neutral top partners. I will review some aspects of neutral naturalness, and discuss some opportunities for progress on the fronts of model building, collider searches and dark matter.  (1410.6808, 1411.7393 and in progress with Matt Strassler, Nathaniel Craig, Pietro Longhi, Dean J. Robinson, Yuhsin Tsai and Marat Freytsis.)

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Contact Information:
David Schaich, Series Director
daschaich@gmail.com
315-415-3277

CM

### Echoes of the Glass Transition in Athermal Soft Spheres

Nov 6, 2015, 11:00 AM-1:00 PM

202/204 Physics

Host: Lisa Manning

The glass transition and the athermal jamming transition are both transitions from one disordered state to another marked by a sudden increase in rigidity. Before the onset of rigidity thermal hard spheres and athermal soft spheres both share the same configuration space. Is there a signature of the glass transition in the topology of the allowed configuration space and is this same signature present for athermal spheres? In this talk, I will answer this question by introducing the concept of local rigidity and demonstrate the existence of a pre-jamming phase transition precisely at the glass transition density.

http://physics.uoregon.edu/profile/peterm/

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Contact Information:
shdavis@syr.edu
315-443-5960

CM

### The Andersen-Parrinello-Rahman Method Revised into a Scale Bridging Device

Oct 28, 2015, 11:00 AM-1:00 PM

202/204 Physics

Host: Matteo Paoluzzi

**NOTE: Wednesday Seminar**

Around 35 years ago, Andersen, Parrinello and Rahman had the idea of letting the molecular-dynamics (MD) cell vary its volume (Andersen) and shape (Parrinello & Rahman) with time. The particle velocity was hence decomposed into the sum of a spatially tidy entrainment velocity, parameterized by the cell deformation rate, and a disordered streaming velocity. In order to govern the collective degrees of freedom associated with the cell, the Lagrangian functional was extended in a smart ad-hoc way. Whether the extended Lagrangian could be derived from “first principles” was a question left for further study, as Parrinello & Rahman themselves stated. In reality, since MD practitioners always considered the APR method just as an expedient trick for generating the desired particle statistics, this foundational issue remained latent until recently, when somebody with a background in continuum mechanics (CM) started looking at the APR method from an antipodal point of view. Here the idea is to bring the deforming computational cell to the fore, identifying it with an element - i.e., an infinitesimally small piece - of a continuous medium. Seen in this perspective, the appealing feature of the APR method is that it establishes a natural, explicit coupling between molecular and continuum DOFs. In conventional applications, dynamical quantities work-conjugate to these latter DOFs - namely, stress - are regarded as prescribed: as a matter of fact, Andersen’s original motivation was that of devising a barostat. In the novel multiscale implementation of the method, the stress is a priori unknown: to determine it, CM PDEs have to be solved concurrently with MD ODEs.

Roughly speaking, the solution strategy goes as follows. Imagine considering a material aggregate as either a molecular system or a continuous medium, and wishing to relate the two representations. Assume that the fields entering the continuum description, such as strain and stress, are adequately sampled on an array of positions (think of Gauss points in a finite element model), whose typical spacing H is enormously larger than the average intermolecular distance d. Associate with each of these macroscopic sampling positions an APR cell, whose reference size h is large enough with respect to d in order to allow for a decent sampling of the microscopic molecular states, and still much smaller than H: H >> h >> d (in practice, it is also essential to take full advantage of the fact that, typically, H/h >> h/d). Now, let the molecules in each cell interact directly with each other (and with their h-neighboring images), while being indirectly affected by those in the H-neighboring cells via the collective degrees of freedom of the deforming APR cell, governed by the force balance and compatibility equations of CM (sampled at the H scale). In turn, the elementwise stress-strain relation characterizing the response of the medium arises as an emergent property of MD (computed on the h scale).

Antonio DiCarlo website

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Contact Information:
shdavis@syr.edu
315-443-5960

HE

### What is a 6D SCFT?

Oct 26, 2015, 2:00 PM-4:00 PM

202 Physics

Host: Scott Watson, gswatson@syr.edu, 315-443-8280

Though long thought not to exist, arguments from string theory strongly indicate the existence of non-trivial interacting conformal field theories in six dimensions.  In this talk, I review the evidence that 6D supersymmetric conformal field theories (SCFTs) exist, and then explain how to use the geometry of extra dimensions to classify all such theories.  A surprising outcome of this work is that all of these theories admit the structure of a simple generalization of quiver (i.e. moose) diagrams used in the study of lower-dimensional quantum field theories.  Time permitting, I will also discuss what we know about these interacting fixed points, and their consequences for understanding quantum field theory in diverse dimensions.

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Contact Information:
David Schaich, Series Director
daschaich@gmail.com
315-415-3277

CM

### Polarization of Cells and Soft Objects Driven by Mechanical Interactions - Consequences for Migration and Chemotaxis

Oct 23, 2015, 11:00 AM-1:00 PM

202/204 Physics

Host: Cristina Marchetti

We study a generic model for the polarization and motility of self-propelled soft objects, biological cells, or biomimetic systems, interacting with a viscous substrate. The active forces generated by the cell on the substrate are modeled by means of oscillating force multipoles at the cell-substrate interface. Symmetry breaking and cell polarization for a range of cell sizes naturally “emerge” from long range mechanical interactions between oscillating units, mediated both by the intracellular medium and the substrate. However, the harnessing of cell polarization for motility requires substrate-mediated interactions. Motility can be optimized by adapting the oscillation frequency to the relaxation time of the system or when the substrate and cell viscosities match. Cellular noise can destroy mechanical coordination between force-generating elements within the cell, resulting in sudden changes of polarization. The persistence of the cell’s motion is found to depend on the cell size and the substrate viscosity. Within such a model, chemotactic guidance of cell motion is obtained by directionally modulating the persistence of motion, rather than by modulating the instantaneous cell velocity, in a way that resembles the run and tumble chemotaxis of bacteria.

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### CUWiP Informational Session

Oct 22, 2015, 3:45 PM-5:45 PM

202/204 Physics

(refreshments 3:30pm)

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Contact Information:
shdavis@syr.edu
315-443-5960

HE

### Galilean Creation of the Inflationary Universe

Oct 16, 2015, 12:30 PM-2:30 PM

208 Physics

Host: Scott Watson, gswatson@syr.edu, 315-443-8280

It has been pointed out that the null energy condition can be violated stably in some non-canonical scalar-field theories. This allows us to consider the Galilean Genesis scenario in which the universe starts expanding from Minkowski spacetime and hence is free from the initial singularity. We use this scenario to study the early-time completion of inflation, pushing forward the recent idea of Pirtskhalava et al. We present a generic form of the Lagrangian governing the background and perturbation dynamics in the Genesis phase, the subsequent inflationary phase, and the graceful exit from inflation, as opposed to employing the effective field theory approach. Our Lagrangian belongs to a more general class of scalar-tensor theories than the Horndeski theory and Gleyzes-Langlois-Piazza-Vernizzi generalization, but still has the same number of the propagating degrees of freedom, and thus can avoid Ostrogradski instabilities. We investigate the generation and evolution of primordial perturbations in this scenario and show that one can indeed construct a stable model of inflation preceded by (generalized) Galilean Genesis.

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Contact Information:
David Schaich, Series Director
daschaich@gmail.com
315-415-3277

CM

### Microswimmer — From Swimming Bacteria to Collective Behaviours of Active Brownian Particles

Oct 16, 2015, 11:00 AM-1:00 PM

202/204 Physics

Host: Cristina Marchetti

Locomotion is a major achievement of biological evolution. Microorganisms, such as bacteria, algae, and sperm cells are equipped with flagella and are able to exploit drag for their propulsion. Two prominent swimming mechanisms are rotating helical flagella, exploited by many bacteria, and snake-like or whip-like motion of eukaryotic flagella, utilized by sperm and algae. Thereby, hydrodynamic interactions play a major role in the swimming motion.

In assemblies of motile microorganisms, cooperativity plays a major role as they exhibit highly organized movements with remarkable large-scale patterns such as networks, complex vortices, or swarms. To unravel the emergent behaviors often simplified models such as active Brownian particles (ABPs) are considered. The generic approaches provide valuable insight into the non-equilibrium statistical aspects of active matter.

In the talk, theoretical and computer simulation results will be presented for the swimming behavior of E. coli bacteria, both in bulk and at surfaces. Moreover, the cooperative dynamics of ABPs will be discussed and a link will be established to the non-equilibrium pressure equation of state.

Roland Winker's webpage

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### Capillary Fracture

Oct 9, 2015, 11:00 AM-1:00 PM

202/204 Physics

Host: Cristina Marchetti

I will describe the initiation and growth of fractures in gels close to their solid-liquid transition, caused by the placement of a fluid droplet on the surface. In experiments, we observe that channel fractures form at the surface of the gel, driven by fluid propagating away from the central droplet. The fractures take the form of starburst-like cracks, with their initiation governed by two processes. First, surface-tension forces exerted by the droplet deform the gel substrate and break azimuthal symmetry. We model the substrate as an incompressible, linear-elastic solid and characterize the elastic response to provide a prediction for the number of fracture arms as a function of material properties and geometric parameters. Second, a thermally-activated process initiates a starburst-shaped collection of fractures corresponding to this strain-patterning. Once initiated, the fractures grow with a universal power law L=t^3/4, with the speed limited by the transport of an inviscid fluid into the fracture tip.

Karen Daniel's webpage

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### Temperature-like Variables in Granular Materials

Oct 8, 2015, 3:45 PM-5:45 PM

202/204 Physics

Host: Jen Schwarz

(refreshments 3:30pm)

Statistical mechanics has provided a powerful tool for understanding the thermodynamics of materials. Because granular materials exhibit reproducible statistical distributions which depend in simple ways on macroscopic parameters such as volume and pressure, it is tempting to create a statistical mechanics of athermal materials. I will describe a suite of experiments on two-dimensional granular materials which investigate to what extent these ideas are meaningful. For example, under agitated conditions, we measure both bulk and particle-scale dynamics, and find a number of thermal-like behaviors including diffusive dynamics, a granular Boyle's Law with a van der Waals-like equation of state, and energy equipartition for rotational and translational degrees of freedom. However, the scarcity of free volume within a granular material provides a crucial control on the dynamics, and each of the above thermal-like behaviors is accompanied by interesting caveats. In an apparatus designed to generate a large number of static configurations, we test whether or not various temperature-like variables are able to equilibrate between a subsystem and a bath. We find that while a volume-based temperature known as "compactivity" fails to equilibrate, a stress-based temperature succeeds. This points to the importance of interparticle forces in controlling the mechanics of granular materials.

Karen Daniel's webpage

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Contact Information:
shdavis@syr.edu
315-443-5960

HE

### Walking and Conformal Dynamics in Many-Flavor QCD on the Lattice

Oct 5, 2015, 2:00 PM-4:00 PM

202 Physics

Host: Simon Catterall, smc@physics.syr.edu, 315-443-5978

In the search for a realistic walking technicolor model, QCD with many flavors, in particular with Nf=8, is an attractive candidate, which has been found to have a composite scalar as light as pion.  Based on lattice simulations with the HISQ action, I will present our lattice results of the scaling properties of various hadron spectra, including the (pseudo)scalar, vector, and baryon channels in comparison with Nf=12 QCD, which is most likely in the conformal phase.  Some implications for dark matter and collider phenomenology in the technicolor model will be also discussed.

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Contact Information:
David Schaich, Series Director
daschaich@gmail.com
315-415-3277

CM

### The Geometry and Mechanics of Growth and Defects

Oct 2, 2015, 11:00 AM-1:00 PM

202/204 Physics

Host: Mark Bowick

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### Hard Problems in Soft Matter - How We Think, Eat, and Protect Ourselves

Oct 1, 2015, 3:45 PM-5:45 PM

202/204 Physics

(refreshments 3:30pm)

Soft matter is the study of matter that easily deforms via thermal fluctuations and/or external and/or internal driving. Given this rather inclusive definition, a vast range of systems falls under the soft matter purview, including brain tissue, cell membranes, biopolymers, and granular materials. I will address (1) how the brain gets its folds to ultimately better understand the interplay between structure and function of the brain, (2) how cells engulf extracellular proteins, i.e. how we eat, with "we" in the collective sense of living systems, and (3) how we (cells and humans) build disordered frameworks with structural integrity (rigidity) to protect ourselves from the "elements".

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Contact Information:
shdavis@syr.edu
315-443-5960

CM

### ***BMCE Seminar***

Sep 25, 2015, 1:00 PM-3:00 PM

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### Leveraging Computational Social Science to Address Grand Societal Challenges

Sep 24, 2015, 9:00 AM-11:00 AM

Strasser Room (220 Eggers Hall)

Kameshwar C. Wali Lecture in the Sciences and Humanities

The increased access to big data about social phenomena in general, and network data in particular, has been a windfall for social scientists. But these exciting opportunities must be accompanied with careful reflection on how big data can motivate new theories and methods. Using examples of his research in the area of networks, Contractor will argue that Computational Social Science serves as the foundation to unleash the intellectual insights locked in big data. More importantly, he will illustrate how these insights offer social scientists in general, and social network scholars in particular, an unprecedented opportunity to engage more actively in monitoring, anticipating and designing interventions to address grand societal challenges.

http://nosh.northwestern.edu

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### The Big Science of Little Neutrinos

Sep 22, 2015, 3:45 PM-5:45 PM

202/204 Physics

(refreshments 3:30pm)

Experimental studies of neutrinos are notoriously challenging due to the feebleness of their interactions with matter, so it may seem counterintuitive to suggest these “little neutral ones” could have played a central role in the development of our universe to its current matter-dominated state. This talk will provide an overview of the interesting physics questions associated with neutrinos, and will give an outlook on the global program to build bigger and better detectors to uncover the answers to these questions.

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Contact Information:
shdavis@syr.edu
315-443-5960

CM

### ***BMCE Seminar***

Sep 18, 2015, 1:00 PM-3:00 PM

Jayaraman Homepage

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### Mechanical Quantum Systems

Sep 17, 2015, 3:45 PM-5:45 PM

202/204 Physics

(refreshments 3:30pm)

The field of mechanical quantum systems has made great strides in recent years developing the technology to begin eliciting and studying quantum behavior of structures that are normally well described by classical laws of physics. While the full potential of the field is yet unknown, it is thought that these mechanical systems could have important applications serving as elements in quantum computing and communication architectures, and could also enable explorations of fundamental topics in quantum mechanics like the quantum-to-classical divide. In my talk, I will first give an overview of this growing field. Then I will highlight ongoing work in my group to develop a particular type of mechanical quantum system - a quantum electromechanical system - that is composed of integrated superconducting circuity and nanomechanical elements and could prove to be an important test-bed for the study of quantum mechanics in new macroscopic limits.

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### Catching Gravitational Waves

Sep 10, 2015, 3:45 PM-5:45 PM

202/204 Physics

(refreshments 3:30pm)

In 1916 Einstein first predicted the existence of gravitational waves. But due to their intrinsic weakness it took almost a century of technological progress to build a receiver capable of detecting gravitational waves. This receiver, a set of laser interferometers with 4km arm length able to detect distance variations as small as one 100'000th the size of an atomic nucleus, is the Advanced Laser Interferometer Gravitational-wave Observatory. It will start its first observation run this fall. Advanced LIGO is designed to observe gravitational waves from the merger of binary neutron stars and black holes, providing the first direct measurements of strong field gravity. I will discuss the current status and sensitivity of the Advanced LIGO detectors, and I will explore options for short and long term upgrades. In particular, I will focus on the two most limiting noise sources: quantum noise of the light and thermal noise, highlighting some of the work done in my group. For lowering the quantum noise, the use of non-classical light looks most promising, and we are focusing on integrating this technology to Advanced LIGO. For mitigating thermal noise several approaches are possible. The most far reaching one will lead us into the design of future gravitational wave detectors, capable of observing mergers of binary neutron stars at red shifts above z=7.

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Contact Information:
shdavis@syr.edu
315-443-5960

CM

### ***BMCE Seminar***

Sep 4, 2015, 1:00 PM-3:00 PM

Velev Group

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### The State of the Universe

Sep 3, 2015, 3:45 PM-5:45 PM

Room 202/204 Physics

(refreshments 3:30pm)

Cosmological observations provide overwhelming evidence that our universe is almost entirely comprised of dark energy and dark matter, both of which have no theoretical explanation within the standard model of particle physics. The former is responsible for a current period of cosmic acceleration, much like that which occurred in the earliest moments of the universe. The early period of cosmic acceleration, known as inflation, was vital in providing the primordial seeds from which galaxies and clusters formed, whereas the late time acceleration could eventually lead to the vanishing of most structure in the universe. The driving force behind cosmic acceleration, as well as dark matter, still remains elusive from the point of view of a microscopic theory. Combined with fundamental questions, such as the origin of particle mass and how electroweak symmetry is broken, these conundrums require physics beyond the standard model. In this talk I will review both the theoretical and observational status of these issues with an emphasis on the excitement surrounding current and upcoming experiments.

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### Department Welcome Reception (Tuesday)

Sep 1, 2015, 3:45 PM-5:45 PM

Room 202/204 Physics

Hosted by the Physics Department

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Contact Information:
shdavis@syr.edu
315-443-5960

TD

### Thesis Defense - Measurement of the Form Factor Shape for the Semileptonic Decay Lb → LcMuNu

Aug 27, 2015, 3:30 PM-5:30 PM

Room 202 Physics

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Contact Information:
shdavis@syr.edu
315-443-5960

TD

### Thesis Defense - The Effects of Spinning Neutron Stars and Hlack Holes on Gravitational-Wave Searches for Binary Neutron Star and Neutron Star - Black Hole Mergers

Aug 20, 2015, 2:00 PM-4:00 PM

Room 208 Physics

TD

### Thesis Defense - Modulation of Charged Biomimetic Membrane by Bivalent Ions

Aug 17, 2015, 3:00 PM-5:00 PM

Room 202 Physics

TD

### Thesis Defense - Beyond Standard Model Physics Under the Ground and in the Sky

Jul 15, 2015, 11:00 AM-1:00 PM

Room 202 Physics

TD

### Thesis Defense - Collective Phenomena in Active Systems

Jul 14, 2015, 10:00 AM-12:00 PM

Room 202 Physics

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Contact Information:
shdavis@syr.edu
315-443-5960

C

### How do Molecules Form in Star-forming Regions?

Jul 13, 2015, 3:00 PM-5:00 PM

208 Physics

Host: Gianfranco Vidali

More than 150 different gas phase molecules and around 20 molecular species on the grain surface have been detected in various regions of the Interstellar Medium (ISM). Many of these molecules are organic, and therefore important astro-biologically. These molecules range in complexity from diatomic H2 to a 15-atom linear nitrile, HC13N. I will discuss how these molecules are formed in a variety of astrophysical sources, with an emphasis on their formation in the star forming regions.

Numerical techniques we developed to study the formation of these molecules include the rate equation method, as well as several more detailed stochastic methods, based upon either the direct solution of the master equation or a Monte Carlo realization of the problem. In this talk, I will present results obtained for diffuse clouds and dust grain mantle compositions, and will discuss their dependence on various physical parameters associated with a star forming region.

CM

### Phase Transitions and Pattern Formation in Myxococcus Xanthus

Jun 5, 2015, 11:00 AM-1:00 PM

202/204 Physics

Host: Cristina Marchetti