Speaker: Virginia Vassilevska Williams (MIT) Title: Clique listing algorithms Abstract: A k-clique in a graph G is a subgraph of G on k vertices in which every pair of vertices is linked by an edge. Cliques are a natural notion of social network cohesiveness with a long history. A fundamental question, with many applications, is […]
https://youtu.be/h3jcSg359E8 New Technologies in Mathematics Seminar Speakers: João Araújo, Mathematics Department, Universidade Nova de Lisboa and Michael Kinyon, Department of Mathematics, University of Denver Title: From Engine to Auto Abstract: Bill McCune produced the program EQP that deals with first order logic formulas and in 1996 managed to solve Robbins' Conjecture. This very powerful tool reduces […]
General Relativity Seminar Speaker: Naqing Xie (Fudan University) Title: Gravitational Wave, Angular Momentum, and Supertranslation Ambiguity Abstract: The supertranslation ambiguity of angular momentum is a long-standing and conceptually important issue in general relativity. Recently, there appeared the first definition of angular momentum at null infinity that is supertranslation invariant. However, in the compact binary coalescence community, supertranslation […]
Algebraic Geometry in String Theory Seminar Speaker: Ahsan Khan, IAS Title: 2-Categories and the Massive 3d A-Model Abstract: I will outline the construction of a 2-category associated to a hyperKahler moment map. The construction is based on partial differential equations in one, two, and three dimensions combined with a three-dimensional version of the Gaiotto-Moore-Witten web formalism. […]
Member Seminar Speaker: Shuaijie Qian (Harvard CMSA) Title: Some non-concave dynamic optimization problems in finance Abstract: Non-concave dynamic optimization problems appear in many areas of finance and economics. Most of existing literature solves these problems using the concavification principle, and derives equivalent, concave optimization problems whose value functions are still concave. In this talk, I will present […]
Quantum Matter Seminar Speaker: Francisco Machado (Berkeley/Harvard) Title: Kardar-Parisi-Zhang dynamics in integrable quantum magnets Abstract: Although the equations of motion that govern quantum mechanics are well-known, understanding the emergent macroscopic behavior that arises from a particular set of microscopic interactions remains remarkably challenging. One particularly important behavior is that of hydrodynamical transport; when a quantum system has a […]
https://youtu.be/T1x60gYry4I Topological Quantum Matter Seminar Speaker: Junyeong Ahn (Harvard) Title: Optical axion electrodynamics Abstract: Electromagnetic fields in a magneto-electric medium behave in close analogy to photons coupled to the hypothetical elementary particle, the axion. This emergent axion electrodynamics is expected to provide novel ways to detect and control material properties with electromagnetic fields. Despite having […]
https://youtu.be/-NisBM-2a2I Speaker: Liang Fu (MIT) Title: Doping and inverting Mott insulators on semiconductor moire superlattices Abstract: Semiconductor bilayer heterostructures provide a remarkable platform for simulating Hubbard models on an emergent lattice defined by moire potential minima. As a hallmark of Hubbard model physics, the Mott insulator state with local magnetic moments has been observed at […]
https://youtu.be/pHDcEX45YKM General Relativity Seminar Speaker: Pengyu Le (BIMSA) Title: Asymptotic geometry of null hypersurface in Schwarzschild spacetime and null Penrose inequality Abstract: Null Penrose inequality is an important case of the well-known Penrose inequality on a null hypersurface. It conjectures the relation between the area of the outmost marginally trapped surface and the Bondi mass at […]
Active Matter Seminar Speaker: Siavash Monfared, Niels Bohr Institute, Copenhagen Title: Force transmission informs the collective behavior of active cell layers Abstract: Collective cell migration drives numerous physiological processes such as tissue morphogenesis, wound healing, tumor progression and cancer invasion. However, how the interplay of mechanical interactions and the modes of collective self-organization among cells informs […]
Swampland Seminar Speaker: Fernando Marchesano (IFT Madrid) Title: EFT strings and emergence Abstract: We revisit the Emergence Proposal in 4d N=2 vector multiplet sectors that arise from type II string Calabi-Yau compactifications, with emphasis on the role of axionic fundamental strings, or EFT strings. We focus on large-volume type IIA compactifications, where EFT strings arise from NS5-branes wrapping […]
Quantum Matter Seminar Speaker: Daniel S. Freed (U Texas) Title: Topological symmetry in field theory Abstract: Recently there has been lots of activity surrounding generalized notions of symmetry in quantum field theory, including “categorical symmetries,” “higher symmetries,” “noninvertible symmetries,” etc. Inspired by definitions of abstract (finite) groups and algebras and their linear actions, we introduce […]