Duality, Marginal Perturbations and Gauging

TL;DR

This paper demonstrates that duality transformations in 2D sigma models with abelian isometries can be viewed as marginal current perturbations, confirming a recent conjecture and revealing specific transformations lead to coset models plus free bosons.

Contribution

It proves that generic dualities are equivalent to marginal current perturbations and clarifies the nature of special dualities resulting in coset models plus free bosons.

Findings

Duality transformations correspond to integrated marginal perturbations.

Generic dualities are equivalent to bilinear current perturbations.

Certain dualities produce coset models with free bosons.

Abstract

We study duality transformations for two-dimensional sigma models with abelian chiral isometries and prove that generic such transformations are equivalent to integrated marginal perturbations by bilinears in the chiral currents, thus confirming a recent conjecture by Hassan and Sen formulated in the context of Wess-Zumino-Witten models. Specific duality transformations instead give rise to coset models plus free bosons.