Speaker: Dan Freed (University of Texas)
Title: What is an anomaly?
Abstract: Anomalies in quantum field theory have been the subject of attention for decades. In this talk I will dispel some myths: anomalies are tied to symmetry, anomalies are tied to fermionic fields, etc. Then I will explain how anomalies--expressed as invertible field theories--are the manifestation of the projectivity of quantum field theory. My point of view is summarized by a slogan: Quantum theory is projective. Quantization is linear.