(De)constructing Intersecting M5-branes

TL;DR

This paper models intersecting M5-branes using a defect conformal field theory derived from D3-branes on an orbifold, revealing symmetry matches and anomalies related to tensionless strings.

Contribution

It introduces a novel dCFT framework for intersecting M5-branes, connecting moduli and symmetries, and identifies an anomaly linked to tensionless strings.

Findings

Matching of SU(2) R-symmetries between dCFT and M5-brane theory

Identification of a 't Hooft anomaly in the SU(2)_L R-symmetry

Connection between tensionless strings and anomalies in intersecting M5-branes

Abstract

We describe intersecting M5-branes, as well as M5-branes wrapping the holomorphic curve xy=c, in terms of a limit of a defect conformal field theory with two-dimensional (4,0) supersymmetry. This dCFT describes the low-energy theory of intersecting D3-branes at a C^2/Z_k orbifold. In an appropriate k -> infinity limit, two compact spatial directions are generated. By identifying moduli of the M5-M5 intersection in terms of those of the dCFT, we argue that the SU(2)_L R-symmetry of the (4,0) defect CFT matches the SU(2) R-symmetry of the N =2, d=4 theory of the M5-M5 intersection. We find a 't Hooft anomaly in the SU(2)_L R-symmetry, suggesting that tensionless strings give rise to an anomaly in the SU(2) R-symmetry of intersecting M5-branes.