Novel Defect Universality Classes from Interacting RG Interfaces

TL;DR

This paper explores new defect universality classes in conformal field theories by analyzing local interactions on RG interfaces, revealing numerous fixed points and new defect configurations with reduced symmetry.

Contribution

It introduces a novel approach to classify defect universality classes using RG interfaces in multiscalar CFTs, uncovering many new fixed points and conformal defects with less symmetry.

Findings

Identification of many new fixed points in defect space.

Interpretation of fixed points as defects within a single bulk with averaged interactions.

Calculation of conformal data and free energy for these RG interfaces.

Abstract

We search for new defect universality classes by considering localised interactions placed on an RG interface separating two interacting multiscalar CFTs in $4-\varepsilon$ dimensions. Studying interactions spread throughout the entire interface as well as defects restricted to lines and surfaces within the interface, we find that this setup leads to a great number of additional physical fixed points in the space of conformal defects. At one loop it is possible to interpret these fixed points as coming from defects placed within a single bulk whose interaction is an average of the two sides. This averaging means that it is possible to identify conformal defects with considerably less global symmetry than was possible beforehand. We finally compute conformal data for this setup, and find the free energy associated with these RG interfaces.