Colloquium (HEP@VUB): 12:00 - 13:00
G/1-G.1.03 - J. Sacton
Building G
External Speaker: Riccardo Argurio (ULB)
The seminar will be done in person and it will be accompanied by sandwiches provided by the VUB.
Title: Quantum Field Theory and Symmetry: A Generalized Story
Abstract: Symmetries in QFT have a long story, involving the definition of a QFT and the characterization of its phases. Symmetries can be spontaneously broken, have anomalies, lead to dualities. We will discuss how we need a generalization of the notion of symmetry to characterize some phases of QFTs, including familiar ones such as confinement. The generalization hinges on recognizing the topological nature of symmetry operators. With this perspective, all the topological sector of a given QFT can describe symmetries, even if they do not form a group. We will discuss examples of theories that enjoy such non-invertible symmetries, and their physical consequences, such as resuscitating an ABJ-anomalous symmetry, and ensuring the degeneracy between vacua with different physical properties.