Algebra Seminar Speaker: Lazar Guterman, Hebrew University of Jerusalem Title: Electrical networks, Grassmannians, and cluster algebras Abstract: An electrical network with $n$ boundary vertices induces a matrix called the response matrix which measures the electrical properties of the network. The set of response matrices of all electrical networks has a characterization in terms of positivity of […]
Geometry and Quantum Theory Seminar Speaker: tba
Geometry and Quantum Theory Seminar Speaker: Daniel Spiegel, Harvard Title: The Quasi-Adiabatic Theorem and All That Abstract: Yosuke Kubota has recently made progress on understanding Kitaev's conjecture by constructing a loop spectrum consisting of spaces of quantum spin systems, indexed by spatial dimension of the lattice (arXiv: 2503.12618). After a brief reminder on the C*-algebraic […]
CMSA Spring Welcome Back Event Date: Jan 28, 2026 Time: 4:00 pm Location: CMSA Common Room, 20 Garden Street, Cambridge MA All CMSA and Math affiliates are invited.
Differential Geometry and Physics Seminar Speaker: Tristan Collins, University of Toronto Title: Complete Calabi-Yau Metrics and Optimal Transport Abstract: I will discuss the connection between optimal transport and the existence of complete Calabi-Yau metrics on log Calabi-Yau varieties. I will explain how the geometric problem of constructing complete Calabi-Yau metrics gives rise to problems in the boundary […]
Algebra Seminar
Member Seminar Speaker: Stephen Landsittel Title: Some results about saturation Abstract: Given a local ring R we can ask when saturation of ideals in R commutes with other operations on ideals (such as extension to a ring containing R). We show that the condition that extension of ideals along a ring map R \to S […]
Freedman Seminar Speakers: Michael Freedman, CMSA and Slava Krushkal, University of Virginia (2-3 pm and 3:15-4:15 pm) Title: Formulating 4D surgery for AI agents Abstract: The topological category surgery exact sequence is still open for free groups (and most groups of exponential growth). The lack of knowledge is about both surgery and s-cobordism; and the […]
Quantum Field Theory and Physical Mathematics Seminar Speaker: Pierre Vanhove (Institute of Theoretical Physics - Saclay) Title: Reflexive Polytopes and the Convergence of Feynman Integrals Abstract: In the parametric representation, Feynman integrals can be viewed as Euler integrals defined by the Symanzik polynomials of a graph. The convergence properties of these integrals are intimately tied […]
Colloquium Speaker: Olivier Bernardi, Brandeis University Title: Bijections for hyperplane arrangements of Coxeter type Abstract: This talk is about real hyperplane arrangements whose hyperplanes are of the form {xi −xj = s} or {xi +xj = s}. We describe a bijective framework for a large family of such arrangements which we call transitive. For each transitive arrangement A, […]
Geometry and Quantum Theory Seminar Speakers: Dan Freed and Bowen Yang, Harvard CMSA Title: More on Kubota's spectrum of invertible states Abstract: Bowen will explain a construction aptly dubbed “Kitaev’s pump” in Kubota’s paper. Time permitting, Bowen will demonstrate its ubiquity throughout the study of topological phases, where it appears under various guises. In the second hour, […]
CMSA Q&A Seminar Speaker: Ludmil Katzarkov, University of Miami Title: New Birational Invariants Abstract: We will introduce the origins of the main ideas of the theory of atoms. Applications follow. Equivariant and mixed atoms will be considered.