Holographic dual of defect CFT with corner contributions

TL;DR

This paper explores the holographic dual of defect conformal field theories, focusing on how corner contributions affect defect operators and revealing new phase behavior at small cusp angles.

Contribution

It introduces a general method for calculating anomalous dimensions of defect changing operators at corners and uncovers a novel bubble phase at near-zero cusp angles.

Findings

Cusp anomalous dimensions are derived analytically for large and small angles.

A universal divergence is observed at small cusp angles due to defect fusion.

A bubble phase emerges at near-zero angles where divergence disappears.

Abstract

We study defect CFT within the framework of holographic duality, emphasizing the impact of corner contributions. We model distinct conformal defects using interface branes that differ in tensions and are connected by a corner. Employing the relationship between CFT scaling dimensions and Euclidean gravity actions, we outline a general procedure for calculating the anomalous dimensions of defect changing operators at nontrivial cusps. Several analytical results are obtained, including the cusp anomalous dimensions at big and small angles. While $1/\phi$ universal divergence appears for small cusp angles due to the fusion of two defects, more interestingly, we uncover a bubble phase rendered by a near zero angle cusp, in which the divergence is absent.