Title: A new approach to O(N) breaking interfaces and boundaries
Abstract: Introducing defects for O(N) critical models in dimension three gives rise to new universality classes of 3D CFTs. One of particular interest, often called extraordinary, corresponds to a breaking of O(N) symmetry to O(N-1). It is often studied through surface defects perturbing the critical O(N) model in three dimensions. In this talk, I will present a different approach and consider a model with cubic interactions on an interface (defect of co-dimension one). I will present the epsilon expansion and computation of CFT data for both finite and large N. In the second part of the talk, I will compare these results with the case of cubic interactions on a boundary.