Nested T-duality

TL;DR

This paper explores the conditions under which T-duality can be applied to boundary WZW models, revealing how specific brane geometries influence the duality and demonstrating a nested relationship between models.

Contribution

It identifies geometric obstructions to T-dualizing boundary WZW models and shows how certain brane configurations enable a nested structure between models.

Findings

Obstructions to T-duality depend on brane geometry.

Certain brane configurations eliminate obstructions.

Boundary WZW model is nested within twisted boundary WZW model.

Abstract

We identify the obstructions for T-dualizing the boundary WZW model and make explicit how they depend on the geometry of branes. In particular, the obstructions disappear for certain brane configurations associated to non-regular elements of the Cartan torus. It is shown in this case that the boundary WZW model is "nested" in the twisted boundary WZW model as the dynamical subsystem of the latter.