String Theory seminar - Akash Jain [UNUSUAL DAY: FRIDAY] Seminar

Abstract: Symmetries and their breaking patterns are a valuable tool in physics for classifying and describing phases of matter. In recent years, a new generalised notion of symmetries has emerged, dubbed "higher-form symmetries", where the associated conserved charges are carried by higher-dimensional objects like strings and surfaces, instead of the usual point-like particles. In this talk, I will give a brief overview of higher-form symmetries and their spontaneous and explicit breaking patterns. In particular, the explicit breaking of higher-form symmetries is associated with the emergence of topological defects in many-body systems. We will outline a new hydrodynamic framework for systems with (approximate) higher-form symmetries and use this to study transitions between topological phases of matter. This includes the melting phase transition in smectic crystals, the plasma phase transition from polarised gases to magnetohydrodynamics, the superfluid to neutral fluid phase transition, and the Meissner effect in superconductors, among many others. The talk will be based on: https://arxiv.org/abs/2301.09628.