Moduli stabilization with positive vacuum energy
E. Dudas, Y. Mambrini
TL;DR
The paper investigates moduli stabilization in string constructions with anomalous U(1) symmetries and fluxes, focusing on D-term uplifting under gauge invariance constraints and the resulting gravitino mass. It finds that conventional D-term uplifting often yields a heavy gravitino unless the FI term is unnaturally small or finely tuned, and that the sign structure of FI terms in orientifold setups can alter the uplift dynamics. As a remedy, it discusses Kahler uplifting, where quantum/corrections to the Kahler potential can enable a de Sitter or Minkowski vacuum with TeV-scale gravitino mass, supported by an explicit example that combines nonperturbative superpotentials with Kahler corrections. The results highlight the importance of including Kahler potential corrections and the detailed anomaly/coupling structure when constructing phenomenologically viable vacua in string theory.
Abstract
We study the effect of anomalous U(1) gauge groups in string theory compactification with fluxes. We find that, in a gauge invariant formulation, consistent AdS vacua appear breaking spontaneously supergravity. Non vanishing D-terms from the anomalous symmetry act as an uplifting potential and could allow for de Sitter vacua. However, we show that in this case the gravitino is generically (but not always) much heavier than the electroweak scale. We show that alternative uplifting scheme based on corrections to the Kahler potential can be compatible with a gravitino mass in the TeV range.