Metastable SUSY Breaking, de Sitter Moduli Stabilisation and K\"ahler Moduli Inflation

TL;DR

This paper explores how anomalous U(1) symmetries and D-terms affect vacuum stability, moduli stabilization, and inflation in string-inspired supergravity models, proposing new mechanisms for de Sitter vacua and inflation without extra uplifting.

Contribution

It introduces a novel realization of LARGE volume scenarios with D-term uplifting to de Sitter space and a supersymmetric approach to Kahler moduli inflation.

Findings

Destabilization of ISS vacuum in simple compactifications.

Construction of de Sitter vacua with D-term and F-term SUSY breaking.

Supersymmetric Kahler moduli inflation with observationally similar properties.

Abstract

We study the influence of anomalous U(1) symmetries and their associated D-terms on the vacuum structure of global field theories once they are coupled to N=1 supergravity and in the context of string compactifications with moduli stabilisation. In particular, we focus on a IIB string motivated construction of the ISS scenario and examine the influence of one additional U(1) symmetry on the vacuum structure. We point out that in the simplest one-Kahler modulus compactification, the original ISS vacuum gets generically destabilised by a runaway behaviour of the potential in the modulus direction. In more general compactifications with several Kahler moduli, we find a novel realisation of the LARGE volume scenario with D-term uplifting to de Sitter space and both D-term and F-term supersymmetry breaking. The structure of soft supersymmetry breaking terms is determined in the preferred scenario where the standard model cycle is not stabilised non-perturbatively and found to be flavour universal. Our scenario also provides a purely supersymmetric realisation of Kahler moduli (blow-up and fibre) inflation, with similar observational properties as the original proposals but without the need to include an extra (non-SUSY) uplifting term.