On D-branes in the Nappi-Witten and GMM gauged WZW models

TL;DR

This paper constructs and classifies D-branes in specific gauged WZW models, providing explicit geometric descriptions and confirming their properties through semiclassical mass calculations aligned with conformal field theory predictions.

Contribution

It explicitly constructs D-branes in NW and GMM gauged WZW models, classifies them using Cardy theorem, and verifies their properties via semiclassical mass calculations.

Findings

Explicit D-brane hypersurface equations in target spaces

Classification of D-branes according to Cardy theorem

Agreement between semiclassical mass and CFT predictions

Abstract

We construct D-branes in the Nappi-Witten (NW) and Guadagnini-Martellini-Mintchev (GMM) gauged WZW models. For the $SL(2,R)\times SU(2)/U(1)\times U(1)$ NW and $SU(2)\times SU(2)/U(1)$ GMM models we present the explicit equations describing the D-brane hypersurfaces in their target spaces. In the latter case we show that the D-branes are classified according to the Cardy theorem. We also present the semiclassical mass computation and find its agreement with the CFT predictions.