Inflation, Gravity Mediated Supersymmetry Breaking, and de Sitter Vacua in Supergravity with a K\"{a}hler-Invariant FI Term

TL;DR

This paper introduces a novel supergravity mechanism for inflation using a Kähler-invariant Fayet-Iliopoulos term, avoiding anti-D3 branes, and explores its implications for supersymmetry breaking and potential string theory realizations.

Contribution

It presents a new supergravity model for inflation with a Kähler-invariant FI term, avoiding R symmetry, and links it to string backgrounds like KKLT without anti-D3 branes.

Findings

Constructed a semi-realistic slow-roll inflation model in supergravity.

Supersymmetry is broken at a high scale with a super-EeV gravitino.

Soft SUSY-breaking terms can be parametrically smaller than the SUSY-breaking scale.

Abstract

We use a new mechanism for generating a Fayet-Iliopoulos term in supergravity, which is not associated to an R symmetry, to construct a semi-realistic theory of slow-roll inflation for a theory with the same K\"ahler potential and superpotential as the KKLT string background (without anti-D3 branes). In our model, supersymmetry must be broken at a high scale in a hidden sector to ensure that the cutoff of the effective field theory is above the Hubble scale of inflation. The gravitino has a super-EeV mass and supersymmetry breaking is communicated to the observable sector through gravity mediation. Some mass scales of the supersymmetry-breaking soft terms in the observable sector can be parametrically smaller than the SUSY breaking scale. If a string realization of the new FI term were found, our model could be the basis for a low energy effective supergravity description of realistic superstring models of inflation.