Title: Symmetry types in QFT and the CRT theorem

Abstract: I will discuss ideas around symmetry and Wick rotation contained in joint work with Mike Hopkins (https://arxiv.org/abs/1604.06527). This includes general symmetry types for relativistic field theories and their Wick rotation.  I will then indicate how the basic CRT theorem works for general symmetry types, focusing on the case of the pin groups.  In particular, I expand on a subtlety first flagged by Greaves-Thomas.