IIA moduli stabilization with badly broken supersymmetry

TL;DR

This paper explores moduli stabilization in string theory using Scherk-Schwarz compactification, resulting in models with broken supersymmetry at the Kaluza-Klein scale and stabilized moduli with small coupling.

Contribution

It provides explicit examples of moduli stabilization with fluxes in models where supersymmetry is badly broken, expanding the landscape of non-supersymmetric string vacua.

Findings

All moduli can be stabilized with small coupling and large internal manifold.

Models are perturbatively stable despite broken supersymmetry.

Supersymmetry breaking occurs at the Kaluza-Klein scale.

Abstract

Scherk-Schwarz compactification in string theory can be defined as orbifolding by an R symmetry, a symmetry that acts differently on bosons and fermions. Such a symmetry can arise in many situations, including toroidal and orbifold compactifications, as well as smooth Calabi-Yau spaces. If the symmetry acts freely then for large radius there are no tachyons in the spectrum. We focus mainly on stabilization by fluxes, and give examples with all moduli stabilized where the coupling is small and the internal manifold is large. Such models appear to be perturbatively stable with supersymmetry broken at the Kaluza-Klein scale. These are interesting laboratories for a variety of theoretical questions and provide models of a non-supersymmetric landscape.