Fox and Hedgehog Seminar Series - 'Categorical symmetries in QFT'

Category theory and representation theory are branches of mathematics concerned with very general collections of objects and how to transform – i.e. exhibit symmetries – between them. There is a recent upsurge of interest from the physics community in the role of categorical representation theory to capture the topological symmetries of physically meaningful quantum field theories. In this seminar I will give an introduction to categories as they appear in QFT, and explain at least two ways how to think of a category as an higher (co-)dimensional enhancement of the fundamental concept of a Hilbert space of states.