Physics Theory Seminar with Carolyn Zhang on Anomalies of non-invertible symmetries

Anomalies of global symmetries are obstructions to flowing to a gapped, symmetric, non-degenerate phase on any manifold. Non-invertible symmetries, like more familiar invertible ones, can also be anomalous. I will describe an approach to answering the following question: given the data describing a non-invertible symmetry in spacetime dimensions, how do we detect whether or not the symmetry is anomalous? The approach that I will focus on uses the symmetry topological field theory, which is a corresponding "inflow" topological quantum field theory in spacetime dimensions. I will use this approach to detect anomalies of simple examples of non-invertible symmetries. 

This lecture was made possible by the William C. Ferguson fund.