The seminar’s scope in broad revolves around theoretical physics and mathematics.

Seed Seminar of Mathematics and Physics

Spontaneous symmetry breaking on surface defects

by Dr Gabriel Cuomo (Department of Physics, Princeton University, Princeton, New Jersey, USA.)





Coleman’s theorem states that continuous internal symmetries cannot be spontaneously broken in two-dimensional quantum field theories (QFTs). I will discuss under which conditions a similar result holds for two-dimensional defects in CFTs invariant under a continuous symmetry group. I will argue that spontaneous symmetry breaking is only possible for exotic RG flows, that do not terminate at a fixed point. I will present examples and describe a generic defect universality class, formerly found by Metlitski for boundaries in the O(N) model, where correlation functions decay logarithmically at large distances.