Discrete Theta Angles, Symmetries and Anomalies

Gauge theories often admit discrete theta angles. Theories with different discrete theta angles can be constructed by gauging a global symmetry in a parent theory with different additional symmetry protected topological (SPT) phases. I will discuss how the global symmetries of these theories and their ‘t Hooft anomalies are controlled by the SPT phases. I will then present examples in various dimensions that exhibit two-group symmetries and non-invertible symmetries. The talk is based on https://arxiv.org/abs/2007.05915 in collaboration with Po-Shen Hsin.

Zoom: https://harvard.zoom.us/j/977347126