Supersymmetric codimension-two branes in six-dimensional gauged supergravity

TL;DR

This paper develops a supersymmetric framework for codimension-2 branes in six-dimensional supergravity, revealing stable unwarped solutions with multiple gravitino zero modes and potential for chiral low-energy spectra.

Contribution

It introduces a method to supersymmetrise tension-carrying branes via localized Fayet-Iliopoulos terms and modifications to the Chern-Simons term, ensuring N=1 supersymmetry.

Findings

Unwarped 'football'-shaped extra dimensions preserve N=1 SUSY.

Multiple gravitino zero modes are found in the background.

Potential for obtaining a single chiral zero mode in the low-energy spectrum.

Abstract

We consider the six-dimensional Salam-Sezgin supergravity in the presence of codimension-2 branes. In the case that the branes carry only tension, we provide a way to supersymmetrise them by adding appropriate localised Fayet-Iliopoulos terms and localised corrections to the Chern-Simons term and modifying accordingly the fermionic supersymmetry transformations. The resulting brane action has N=1 supersymmetry (SUSY). We find the axisymmetric vacua of the system and show that one has unwarped background solutions with "football"-shaped extra dimensions which always respect N=1 SUSY for any value of the equal brane tensions, in contrast with the non-supersymmetric brane action background. Finally, we generically find multiple zero modes of the gravitino in this background and discuss how one could obtain a single chiral zero mode present in the low energy spectrum.