Speaker
Description
Interfaces in conformal field theory (CFT) appear in many contexts and sometimes play a crucial role in characterizing the theory. For example, topological interfaces have long been studied (such as the name of Verlinde lines) and there exist well-developed methods to extract the information they encode. By contrast, conformal interfaces that are not necessarily topological but conformal, such as RG interfaces, are more complicated and typically much harder to analyze.
In this work, we propose a universal method to compute the transmission coefficient associated with a conformal interface between two CFTs that is assumed to be conformal. The key idea is to make use of a spin-2 non-local operator, a “phantom current,” which emerges when folding two theories; under a certain assumption, this allows us to compute the transmission coefficient. In this talk, I will explain this method in detail and discuss its consistency with previously known examples. This talk is based on arXiv:2511.00356.
