Quantum Matter Seminar Speaker: Brandon C. Rayhaun (C. N. Yang ITP, Stony Brook University) Title: Small Bosonic CFTs, Chiral Fermionization, and Symmetry/Subalgebra Duality Abstract: Conformal field theories in (1+1)D are key actors in many dramas of physics and mathematics. Their classification has therefore been an important and long-standing problem. In this talk, I will explain […]
Quantum Matter Seminar Title: Chiral fermionic CFTs of central charge ≤ 16 Abstract: We classified all chiral fermionic CFTs of central charge ≤ 16 using Kac's theorem and bosonization/fermionization. This talk will discuss the derivation of this result, its application to the classification of non-supersymmetric heterotic string theories, and along the way we'll address some […]
Quantum Matter Seminar Speaker: Marieke Van Beest (SCGP) Title: Monopoles, Scattering, and Generalized Symmetries Abstract: In this talk, we will discuss the problem of electrically charged, massless fermions scattering off magnetic monopoles. The interpretation of the outgoing states has long been a puzzle, as they can carry fractional quantum numbers. We argue that such outgoing […]
General Relativity Seminar Speaker: Suman Kundu (Weizmann Institute) Title: ‘Grey Galaxy’ as the endpoint of the Kerr-AdS super radiant blackhole Abstract: Kerr AdS$_{d+1}$ black holes for $d\geq 3$ suffer from classical superradiant instabilities over a range of masses near extremality. We conjecture that these instabilities settle down into Grey Galaxies (GG)s - a new class of […]
Quantum Matter Seminar Speaker: John Baez (University of California, Riverside) Title: Two of my favorite numbers: 8 and 24 Abstract: The numbers 8 and 24 play special roles in mathematics. The number 8 is special because of Bott periodicity, the octonions and the E8 lattice, while 24 is special for many reasons, including the binary […]
https://www.youtube.com/playlist?list=PL0NRmB0fnLJTEIjTUSrZ206RAiMRZHCuh On August 31-Sep 1, 2023 the CMSA hosted the ninth annual Conference on Big Data. The Big Data Conference features speakers from the Harvard community as well as scholars from across the globe, with talks focusing on computer science, statistics, math and physics, and economics. Speakers: Jacob Andreas, MIT Morgane Austern, Harvard Albert-László Barabási, […]
Probability Seminar Speaker: Marius Lemm, University of Tuebingen Title: Light cones for open quantum systems Abstract: We consider non-relativistic Markovian open quantum dynamics in continuous space. We show that, up to small probability tails, the supports of quantum states propagate with finite speed in any finite-energy subspace. More precisely, if the initial quantum state is localized […]
Probability Seminar Speaker: Arka Adhikari (Stanford) Title: Correlation decay for finite lattice gauge theories Abstract: In the setting of lattice gauge theories with finite (possibly non-Abelian) gauge groups at weak coupling, we prove exponential decay of correlations for a wide class of gauge invariant functions, which in particular includes arbitrary functions of Wilson loop observables. […]
Quantum Matter Seminar Speaker: Xiao-Gang Wen (MIT) Title: A 6-year journey: from gravitational anomaly to a unified theory of generalized symmetry Abstract: Emergent symmetry can be generalized symmetry beyond (higher) group description and/or can be anomalous. I will describe a unified theory for generalized symmetry based on symmetry/topological-order correspondence. I will also discuss some applications […]
https://youtu.be/cxdPO4L4GDk General Relativity Seminar Speaker: Diandian Wang(Harvard University) Title: Pole skipping, quasinormal modes, shockwaves and their connection to chaos Abstract: A chaotic quantum system can be studied using the out-of-time-order correlator (OTOC). I will tell you about pole skipping — a recently discovered feature of the retarded Green’s function — that seems to also know things: things like the Lyapunov […]
https://youtu.be/vYXTKTmNFHg Topological Quantum Matter Seminar Speaker: Roman Geiko, UCLA Title: Homotopy classes of loops of Clifford unitaries Abstract: We study Clifford locality-preserving unitaries and stabilizer Hamiltonians by means of Hermitian K-theory. We demonstrate how the notion of algebraic homotopy of modules over Laurent polynomial rings translates into the connectedness of two short-range entangled stabilizer Hamiltonians […]
Topological Quantum Matter Seminar Speaker: Xueyang Song (MIT) Title: Phase transitions out of quantum Hall states in moire TMD bilayers Abstract: Motivated by the recent experimental breakthroughs in observing Fractional Quantum Anomalous Hall (FQAH) states in moir\'e Transition Metal Dichalcogenide (TMD) bilayers, we propose and study various unconventional phase transitions between quantum Hall phases and Fermi […]