Generalized non-supersymmetric flux vacua

TL;DR

The paper develops a 10D framework to construct and analyze non-supersymmetric flux vacua in type II string theory by exploiting generalized calibrations within Generalized Complex Geometry. It shows that partial BPS bounds for D-branes can stabilize 4D vacua even when domain walls fail to be BPS, leading to a no-scale Minkowski class (the DWSB backgrounds) that generalizes GKP setups. A tractable one-parameter subfamily is singled out, yielding explicit no-scale DWSB vacua and enabling computation of flux-induced soft terms on D-branes, including gaugino masses and other fermionic couplings, with clear 4D/F-term interpretations. The work also extends integrability techniques to the ${ m N}=0$ setting, producing AdS$_4$ vacua and providing a complementary 10D route to non-supersymmetric backgrounds, while magnetized/beta-deformed and SU(3) or SU(2) structure subcases illustrate rich geometric realizations and phenomenological implications for soft terms and brane dynamics.

Abstract

We discuss a novel strategy to construct 4D N=0 stable flux vacua of type II string theory, based on the existence of BPS bounds for probe D-branes in some of these backgrounds. In particular, we consider compactifications where D-branes filling the 4D space-time obey the same BPS bound as they would in an N=1 compactification, while other D-branes, like those appearing as domain walls from the 4D perspective, can no longer be BPS. We construct a subfamily of such backgrounds giving rise to 4D N=0 Minkowski no-scale vacua, generalizing the well-known case of type IIB on a warped Calabi-Yau. We provide several explicit examples of these constructions, and compute quantities of phenomenological interest like flux-induced soft terms on D-branes. Our results have a natural, simple description in the language of Generalized Complex Geometry, and in particular in terms of D-brane generalized calibrations. Finally, we extend the integrability theorems for 10D supersymmetric type II backgrounds to the N=0 case and use the results to construct a new class of N=0 AdS4 compactifications.