Abstract
Symmetries play a central role in all fields of modern physics, the study of which allows us to characterize various properties of a physical system. Notable examples of such applications include the Standard Model of particle physics and the Landau paradigm, which respectively classify elementary particles and phases of matter. The intrinsic notion of “symmetries” in quantum field theory (QFT), however, has undergone several revolutionary generalizations in the past decade. Importantly, a symmetry of a QFT is most generally associated with topological operators which may or may not be mathematically described by groups. The latter case is often referred to as “non-invertible symmetries” in the high-energy theory and condensed matter literatures. In this talk, I will discuss an explicit example of non-invertible symmetries in a 4d QFT, and show how the non-invertibility can be attributed to a dynamical process in string theory known as “tachyon condensation” on D-branes. This result sheds light on the understanding of non-invertible symmetries from a holographic perspective. If time permits, I will also argue that to systematically study symmetries in a QFT, we need a new mathematical framework known as higher fusion categories in place of traditional groups.
Anyone interested is welcome to attend.