Defect Lines and Boundary Flows

TL;DR

This paper explores how defect lines influence boundary renormalization group flows, revealing that boundary flows between certain conditions can be extended via fusion, with implications for understanding boundary dynamics.

Contribution

It introduces a novel property of defect lines that allows boundary flows to be extended through fusion, providing new insights into boundary RG flows.

Findings

Boundary flows between conditions 'a' and 'b' imply flows between 'c x a' and 'c x b' via fusion.

Fusion product 'x' preserves the existence of boundary flows.

Applications of the fusion-based boundary flow extension are discussed.

Abstract

Using the properties of defect lines, we study boundary renormalisation group flows. We find that when there exists a flow between maximally symmetric boundary conditions "a" and "b" then there also exists a boundary flow between "c x a" and "c x b" where "x" denotes the fusion product. We also discuss applications of this simple observation.