MPS Annual Meeting 2021

Xie Chen
California Institute of Technology

Quantum Error Correction Codes as Exotic Condensed Matter

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To achieve more robust computation and communication processes with quantum information, quantum error correction codes were invented to protect the information from noise and decoherence. The codes consist of specifically designed, contrived quantum states, yet some of them have become hot topics in condensed matter physics, an area which is traditionally grounded in measurable phenomena in real-world solid-state materials. Xie Chen will explain how these error correction codes reveal possible novel physics phenomena and inspire the exploration of new phases in condensed matter system. At the same time, connecting them to real experimental system provides a path forward to realizing the robust information processing protocols.

Xie Chen studies exotic topological phenomena that can emerge in strongly interacting quantum many-body systems. Her work uses ideas and tools in quantum information to explore topological states of matter and study the relationships between them. She discovered and systematically constructed symmetry-protected topological phases in strongly interacting systems in two and higher dimensions. She proposed methods to classify and detect anomaly in symmetry-enriched topological phases. Recently, her work on fracton phases generalized the notion of phase and universality to properly capture the unusual ‘beyond topology’ phenomena discovered in certain quantum error correction codes.

Jane Kondev
Brandeis University

How Cells Measure Length

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Gulliver noticed 140 years ago that the size of the cell’s nucleus is proportional to the size of the cell. In the intervening years, similar observations have been made about other, large structures that self-assemble in the cell. This raises a fascinating question: How does the cell, which is micrometers in length, measure its size with nothing more at its disposal than nanometer-sized proteins that diffuse, on occasion bump into each other, and transiently stick together? In this talk, I Jane Kondev will describe quantitative experiments and related theory that reveal general principles of how cells measure their size and control the size of their internal structures. The case of self-assembly of actin cables in budding yeast is particularly interesting in this context, as it provides an example of a cell controlling the length of a large, filamentous structure. Kondev will describe experiments and theory pertaining to this specific problem, which gets at the general question of how cells measure length?

Jane grew up in New York and Belgrade (Serbia). He did his doctoral work at Cornell in theoretical physics, and after research fellowships as Brown and Princeton, he settled down at Brandeis where he is the William R. Kenan, Jr. Professor of Physics, and a Professor of the Howard Hughes Medical Institute. He is the coauthor of the book “Physical Biology of the Cell” which won the Society of Biology Book Award. His group at Brandeis brings together math, physics, and biology students united by their interest in developing quantitative models of living systems. Current research in the group focuses of gene expression, cytoskeleton assembly, and chromosome dynamics.

Bryna Kra
Northwestern University

Symmetries in Symbolic Dynamics

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Symbolic dynamics, originating in the work of Hadamard in the 1890’s, is a key tool for studying topological, smooth, and measurable dynamical systems. The automorphism group of a symbolic system captures its symmetries, reflecting the dynamical behavior and the complexity of the system. Bryna Kra will give an overview of relations among dynamical properties of the system algebraic properties of the automorphism, and measurable properties of associated systems. 


Bryna Kra is the Sarah Rebecca Roland Professor of Mathematics at Northwestern University. She earned her doctorate from Stanford University and held positions at the University of Jerusalem in Israel, the Institute des Hautes Etudes Scientifiques in France, at the University of Michigan, the Ohio State University, and Pennsylvania State University, before joining the faculty at Northwestern University in 2004.

Kra was awarded the Centennial Fellowship of the American Mathematical Society in 2006 and the Conant Prize of the American Mathematical Society in 2010 and was elected an inaugural fellow of the American Mathematical Society in 2012. In 2016, she became a fellow of the American Academy of Arts and Sciences and in 2019 she was elected to the National Academy of Sciences. Kra works in ergodic theory and dynamical systems, particularly on problems motivated by combinatorics and number theory.

Elchanan Mossel
Massachusetts Institute of Technology

Mathematical Aspects of Opinion Dynamics

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One feature (bug?) of this time is that our opinions and preferences are analyzed, manipulated and aggregated at an unprecedented scale and sophistication.

This talk will survey mathematical results and models that aim to provide insights on these processes and their outcomes.

Elchanan Mossel is a Professor of Mathematics at the Massachusetts Institute of
Technology. His research spans a number of topics across probability, statistics, economics, computer science, and mathematical biology. He is known for his work in discrete Fourier analysis and its applications to computational complexity and social choice theory and for his research of information flow in biological, economic, and inferential networks.

Mossel held a Sloan Fellowship. He is a fellow of the American Mathematical Society, a Simons Fellow and a Vannevar Bush Fellow.

Rahul Nandkishore
University of Colorado, Boulder

Fracton Dynamics

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Rahul Nandkishore will introduce a new class of quantum states of matter, known as `fracton phases.’ He will explain how these phases provide a new frontier for quantum dynamics, offering novel routes to ergodicity breaking and subdiffusion. Nandkishore will also comment on how insights gleaned from the study of fractons can be applied to quantum dynamics in broader, non-fractonic contexts.
 
Rahul Nandkishore received his PhD from MIT in 2012. He then spent time as a postdoctoral fellow at the Princeton Center for Theoretical Science, before joining the faculty at the University of Colorado Boulder in 2015. He has been in Boulder ever since, receiving tenure in 2020. 

Nandkishore is known for his work on interaction and disorder effects in graphene and other Dirac fermion systems, and also for his work on many body quantum systems out of equilibrium. In the latter context, he is known for introducing the notion of eigenstate order and eigenstate phase transitions, for demonstrating that many body localization can occur in systems with long range interactions, and for elucidating the rich quantum dynamics of fracton phases of quantum matter. Nandkishore is the recipient of Young Investigator awards from the US Air Force Office of Sponsored Research and US Army Research Office, of a Sloan Research Fellowship, and of a Simons Fellowship in Theoretical Physics. 

Karin Öberg
Harvard University

Astrochemical Origins of Solar System Compositions

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Over the past decades we have obtained more and more precise data on the compositions of Solar System bodies: the Galileo and Juno probes have revealed the elemental composition of Jupiter’s envelope, the Rosetta mission has provided a very detailed inventory of one comet while ground-based observations of comets have mapped out the range of possible comet abundances, and analyses of meteorites continue to reveal the composition of the building blocks of inner Solar System planets etc. This wealth of data has deepened our understanding of the Solar System and its origin. But it has also presented many puzzles, including the origins of Jupiter’s envelope, of water-poor comets, of missing carbon in the inner Solar System, and of prebiotically interesting molecules in multiple Solar System objects. In this talk, Karin Öberg will explore these puzzles from an astrochemical point of view, using astrochemical models, which were often developed to explain observations of exoplanets or of planet-forming disks around other stars. Öberg will also introduce some of the observational and experimental data that have enabled us to benchmark these models.

Karin Öberg is Professor of Astronomy at Harvard University. Her specialty is astrochemistry and her research aims to uncover how chemical processes affect the outcome of planet formation, especially the chemical habitability of nascent planets. Her research group approaches this question through laboratory experiments, simulating the exotic chemistry that gives rise to chemical complexity in space, through astrochemical modeling, and through astronomical observations of molecules in planet-forming disks around young stars.

Dr. Öberg left Sweden for Caltech in 2001, where she matriculated with a B.Sc. in chemistry in 2005. Four years later she obtained a Ph.D. in astronomy, with a thesis focused on laboratory astrochemistry. In 2009 she moved to the Harvard-Smithsonian Center for Astrophysics with a Hubble fellowship, focusing on millimeter observations of protoplanetary disks. In 2013 she joined the Harvard Astronomy faculty as an assistant professor, was promoted and named the Thomas D. Cabot Associate Professor in Astronomy in 2016 and promoted to full professor with tenure in 2017. Dr. Öberg’s research in astrochemistry has been recognized with a Sloan fellowship, a Packard fellowship, the Newton Lacy Pierce Award, and a Simons Investigator Award.

Eleonora Presani
Cornell University

arXiv: Reinventing Scholarly Communication For 30 Years

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Since 1991, arXiv has changed the way researchers communicate with each other. Starting only in high energy physics, today arXiv covers 8 subject areas, with 1.8M posted articles and over 5M monthly users. arXiv has filled a need in scholarly communication, allowing researchers to share their work early, quickly and for no charge. After 30 years, these needs are still at the very center of arXiv service. At the same time, it is exciting to look at the next 30 years and imagine how arXiv can transform the lives of researchers worldwide. This presentation will discuss the major current and future plans for arXiv, as well as challenge the audience to consider the most interesting problems that scholarly communication will face in the next decade.

As executive director, Dr. Eleonora Presani leads strategic, technical, and business planning for arXiv, the world’s premier open research-sharing platform. Her focused, and solutions-oriented approach have led to numerous enhancements and collaborations since she started the position in 2020. Her work to advance open science and sustainable publishing is informed by her previous experience as an astroparticle physics researcher and as a publisher and product manager at Elsevier. Driven by a passion for science, she believes that a combination of technology and empathy are the key ingredients to enable researchers worldwide to sustainably, effectively advance science in an equitable, inclusive environment. Originally from Trieste (Italy), Dr. Presani trained at CERN, University of Amsterdam, University of Trieste, and Université Paris Sud XI.

Sylvia Serfaty
New York University

Coulomb Gases and Vortex Systems

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Sylvia Serfaty will discuss some mathematical analysis of systems of points with Coulomb (or sometimes more general singular) interactions, which arise in condensed matter physics (superconductors, superfluids, Bose-Einstein condensates), in statistical and quantum mechanics (one and two-component plasmas, fractional quantum Hall effect, random matrix models) and in approximation theory. They give rise to a variety of questions pertaining to analysis, Partial Differential Equations, probability and number theory.

Sylvia Serfaty is Silver Professor at the Courant Institute of Mathematical Sciences of New York University. Prior to this she has been Professor at Sorbonne Université, and has held various appointments at the Courant Institute of NYU. She earned her BS and MS in Mathematics from the École Normale Supérieure in Paris in 1995, and her PhD from Université Paris Sud in 1999. She is interested in Partial Differential Equations, mathematical physics and statistical mechanics. She was a plenary speaker at the International Congress of Mathematicians in 2018, the recipient of the European Mathematical Society and Henri Poincaré prizes, and is a member of the American Academy of Arts and Sciences.

Eleni Katifori, University of Pennsylvania

Flow Networks in Flux

Transport webs span a broad range of length scales, from microns in the human microcirculation to kilometers in river networks. The structure of all these networks is mutable and subject to either gradual, irreversible change, as in the case of river evolution in geological timescales, or reversible change, as in the case of the adaptation of human circulation to a faster heart rate in mere seconds. These changes are frequently brought about by flow that runs through channels, providing an active feedback between the currents and the channel conductances. As these networked systems are strongly coupled via the flow — a local disturbance in the network will be “felt” in a broad neighborhood around the site — dynamical adaptation allows the networks to self-organize and exhibit rich behaviors that are sometimes counterintuitive.

In this talk, Eleni Katifori will explore some of this rich phenomenology and, among other questions, try to understand how tides shape river deltas, explain how loopiness emerges in leaf vasculature and calculate the price of having a pulse.

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