String Theory seminar - Itamar Yaakov Seminar

Abstract: Recent work on generalized symmetries has rekindled the community’s interest in finding a mathematically rigorous construction for QFT. Unfortunately, this dream does not seem to be close at hand. A more modest goal, however, does seem to be within reach: to clarify the abstract symmetry structure of a generic QFT using tools from TQFT. In this talk, I will give a brief introduction to TQFT, topological defects, and their connection with generalized symmetries. I will then review some of my past and ongoing work on constructing defect operators in gauge theories, with and without supersymmetry, and highlight their interaction with the abstract symmetry structure. Specifically, I will emphasize the way in which non-topological defects, especially charged objects, provide a dual viewpoint on symmetries and phases of gauge theories. The student session will feature a lightning review of supersymmetric localization and its connection to TQFT.