Generalised permutation branes

TL;DR

This paper introduces a new class of non-factorising D-branes in product groups, extending known permutation branes to cases with differing fluxes and metrics, supported by Lagrangian and Dirac-Born-Infeld analyses.

Contribution

It proposes generalized permutation branes with non-coincident fluxes and metrics, expanding the understanding of D-branes in product groups beyond symmetric cases.

Findings

Existence of these branes supported by Lagrangian and Dirac-Born-Infeld theories.

Explicit geometry, gauge fields, and tensions for SU(2)xSU(2).

Provides a K-theory charge classification including torsion.

Abstract

We propose a new class of non-factorising D-branes in the product group GxG where the fluxes and metrics on the two factors do not necessarily coincide. They generalise the maximally symmetric permutation branes which are known to exist when the fluxes agree, but break the symmetry down to the diagonal current algebra in the generic case. Evidence for the existence of these branes comes from a Lagrangian description for the open string world-sheet and from effective Dirac-Born-Infeld theory. We state the geometry, gauge fields and, in the case of SU(2)xSU(2), tensions and partial results on the open string spectrum. In the latter case the generalised permutation branes provide a natural and complete explanation for the charges predicted by K-theory including their torsion.