Algebra Seminar Speaker: Aryaman Maithani, University of Utah Title: Polynomial invariants of conjugation over finite fields Abstract: Consider the conjugation action of GL₂(K) on the polynomial ring K. When K is an infinite field, the ring of invariants is a polynomial ring generated by the trace and the determinant. We describe the ring of invariants when K is a finite field, and show that it is a hypersurface.
Colloquium Speaker: Anuj Srivastava, Johns Hopkins University Title: Statistical Shape Analysis of Complex Natural Structures Abstract: Statistical modeling and analysis of structured data is a fast-growing field in Statistics and Data Science. Rapid advances in imaging techniques have led to tremendous amounts of data for analyzing imaged objects across several scientific disciplines. Examples include shapes […]
Quantum Field Theory and Physical Mathematics Seminar Speaker: Matthew Yu (University of Oxford) Title: When do anomalous finite symmetries in (3+1)d enforce gaplessness? Abstract: I will explain a comprehensive framework for characterizing the infrared (IR) phases of a fermionic QFTs in (3+1)d, based on their quantum anomalies associated with a finite symmetry. We uncover a […]
Member Seminar Speaker: Keyou Zeng Title: From Poincaré/Koszul duality to (twisted) AdS/CFT correspondence Abstract: Poincaré duality is a fundamental result in the (co)homology theory of manifolds. It has many applications in topology and vast generalizations to other types of “spaces,” such as singular/stratified spaces and schemes. In this talk, I will discuss a variant of Poincaré duality […]
Colloquium Speaker: Nikita Nekrasov, Simons Center Title: Dynamics as intersection problem Abstract: Most classical and quantum field theories are based on an action principle. However, there are important exceptions to this --- hydrodynamics and the theory of self-dual fields. In this talk we formulate the covariant relativistic fluid dynamics, with or without magnetic fields, as […]
Quantum Field Theory and Physical Mathematics Seminar Speaker: Surya Raghavendran, Yale University Title: Twisted D-branes and TQFTs valued in Calabi-Yau categories Abstract: Recently, Bozec–Calaque–Scherotzke have articulated a noncommutative version of the AKSZ construction, which associates to a smooth Calabi–Yau category a fully extended TQFT valued in a category of iterated Calabi–Yau cospans. In this talk, […]
Member Seminar Speaker: Iacopo Brivio, CMSA Title: Lifting F-split surfaces to the Witt vectors Abstract: Algebraic varieties in positive characteristic are ill behaved compared to characteristic zero ones. Several important tools available over the complex numbers, such as the Hodge decomposition theorem, are either not available or straight-away false. There are two important classes of […]
Colloquium Speaker: Ofer Feinerman, Weizmann Institute of Science Title: Enacted collective cognition: Brainless problem-solving in weaver ants Abstract: Unlike most ants, weaver ants construct their nests by pulling together leaves. Because individual ants are small relative to the leaves, they assemble their bodies into temporary tools that bend the leaves into a hollow structure, later […]
Member Seminar Speaker: Daniel Spiegel Title: The Intermingling of Symmetry and Parametrization in Matrix Product States Abstract: In the study of quantum spin systems, it is by now well-known that interesting phases of quantum matter can arise from gapped ground states when the system is invariant under a symmetry group G or when the system varies continuously […]
Differential Geometry and Physics Seminar Speaker: François Greer, MSU Title: Boundedness for K-trivial varieties with fibrations Abstract: According to the Beauville-Bogomolov decomposition theorem, any smooth K-trivial variety admits a finite cover by a product of (1) abelian varieties, (2) strict Calabi-Yau varieties, and (3) irreducible holomorphic symplectic varieties (IHSV). In a fixed dimension, all abelian varieties […]
https://youtu.be/91-jAKfUpRY CMSA/Tsinghua Math-Science Literature Lecture Date: April 22, 2026 Time: 9:00 - 10:30 am ET Location: via Zoom Webinar Speaker: Nicolai Reshetikhin, Yau Mathematical Sciences Center, Tsinghua University Title: Asymptotic representation theory Abstract: Loosely speaking asymptotic representation theory studies representations of “large” groups or algebras. One of the first results in this direction is the study […]
Quantum Field Theory and Physical Mathematics Seminar Speaker: Lorenzo Riva (Harvard CMSA) Title: Zigzags, adjoints, and bordisms Abstract: We will learn how to freely add adjoints to a category using a combinatorial procedure which involves drawing zigzags of squares. Peculiarly, we can use these to draw some bordisms. This is joint work with Martina Rovelli.