• Multipartitioning topological phases and quantum entanglement

    Virtual

    Speaker: Shinsei Ryu (Princeton University) Title: Multipartitioning topological phases and quantum entanglement Abstract: We discuss multipartitions of the gapped ground states of (2+1)-dimensional topological liquids into three (or more) spatial regions that are adjacent to each other and meet at points. By considering the reduced density matrix obtained by tracing over a subset of the regions, we […]

  • Exact Eigenstates in Non-Integrable Systems: A violation of the ETH

    Virtual

    Speaker: B. Andrei Bernevig (Princeton University) Title: Exact Eigenstates in Non-Integrable Systems: A violation of the ETH Abstract: We find that several non-integrable systems exhibit some exact eigenstates that span the energy spectrum from lowest to the highest state. In the AKLT Hamiltonian and in several others “special” non-integrable models, we are able to obtain the analytic […]

  • Quantum Geometric Aspects of Chiral Twisted Graphene Models

    Virtual

    Speaker: Jie Wang (Simons Foundation) Title: Quantum Geometric Aspects of Chiral Twisted Graphene Models Abstract: “Moire” materials produced by stacking monolayers with small relative twist angles are of intense current interest for the range of correlated electron phenomena they exhibit. The quench of the kinetic energy means that the interacting physics is controlled by the interplay between […]

  • Non-Invertible Duality Defects in 3+1 Dimensions

    Virtual

    Speaker: Clay Cordova (U Chicago) Title: Non-Invertible Duality Defects in 3+1 Dimensions Abstract:  For any quantum system invariant under gauging a higher-form global symmetry, we construct a non-invertible topological defect by gauging in only half of spacetime. This generalizes the Kramers-Wannier duality line in 1+1 dimensions to higher spacetime dimensions. We focus on the case of a […]

  • Anomaly resolution via decomposition

    Virtual

    Speaker: Eric Sharpe (Virginia Tech) Title: Anomaly resolution via decomposition Abstract: In this talk we will discuss a method of anomaly resolution due to Wang-Wen-Witten in the special case of (1+1) dimensional theories. Briefly, for our purposes, Wang-Wen-Witten argued that an ill-defined anomalous orbifold could be resolved by extending G to a larger group and […]

  • Categorification and applications

    Virtual

    Speaker: Peng Shan (Tsinghua University) Title: Categorification and applications Abstract: I will give a survey of the program of categorification for quantum groups, some of its recent development and applications to representation theory.

  • D3C: Reducing the Price of Anarchy in Multi-Agent Learning

    Virtual

    Speaker: Ian Gemp, DeepMind Title: D3C: Reducing the Price of Anarchy in Multi-Agent Learning Abstract: In multi-agent systems the complex interaction of fixed incentives can lead agents to outcomes that are poor (inefficient) not only for the group but also for each individual agent. Price of anarchy is a technical game theoretic definition introduced to quantify the […]

  • A tour of categorical symmetry

    Virtual

    Title: A tour of categorical symmetry Abstract: I will discuss some perspectives on symmetry coming from the study of topological defects in quantum field theory. I will argue that we should take topological defects themselves to define the symmetries of QFT. This gives us a view of the “category of QFTs”. I will describe some […]

  • Line defects in CFTs: Renormalization group flows and semiclassical limits

    Virtual

    Title: Line defects in CFTs: Renormalization group flows and semiclassical limits Abstract: I will discuss line defects in d-dimensional Conformal Field Theories (CFTs). In the first part of the talk, I will argue that the ambient CFT places nontrivial constraints on Renormalization Group (RG) flows on such line defects. I will show that the flow […]

  • Strings, knots and quivers

    Virtual

    Speaker: Piotr Sułkowski (University of Warsaw) Title: Strings, knots and quivers Abstract: I will discuss a recently discovered relation between quivers and knots, as well as – more generally – toric Calabi-Yau manifolds. In the context of knots this relation is referred to as the knots-quivers correspondence, and it states that various invariants of a given knot […]