Global gauge anomalies in coset models of conformal field theory

TL;DR

This paper classifies when global gauge anomalies occur in coset models of 2D conformal field theory based on gauged WZW models, using Lie algebra substructure analysis.

Contribution

It provides a comprehensive classification of non-anomalous coset models in 2D conformal field theory using Dynkin's Lie algebra subalgebra classification.

Findings

Complete classification of anomaly-free models

Identification of conditions for non-anomalous gauged symmetries

Application of Lie algebra substructure to conformal field theory

Abstract

We study the occurrence of global gauge anomalies in the coset models of two-dimensional conformal field theory that are based on gauged WZW models. A complete classification of the non-anomalous theories for a wide family of gauged rigid adjoint or twisted-adjoint symmetries of WZW models is achieved with the help of Dynkin's classification of Lie subalgebras of simple Lie algebras.