Gravitational Waves and Gravitino Mass in No-Scale Supergravity Inflation with Polonyi Term

TL;DR

This paper explores a supergravity inflation model with a Polonyi term, predicting observable gravitational waves and linking gravitino mass to gravitational wave energy density.

Contribution

It introduces a non-minimal Kähler potential and Polonyi term in supergravity inflation, connecting gravitational wave signals with gravitino mass predictions.

Findings

Gravitational waves could be detected by upcoming interferometers.

Polonyi term enhances gravitational wave energy density.

Gravitino mass is correlated with gravitational wave signals.

Abstract

We study a No-Scale supergravity inflation model which has a non-minimal deformation of the K\"ahler potential and a Wess-Zumino superpotential extended by the inclusion of a Polonyi mass term. The non-minimal structure of the K\"ahler potential is responsible for an inflexion point that can lead to the production of gravitational waves at late stages of inflation, while the Polonyi term breaks supersymmetry at the end of inflation, generating a non-vanishing gravitino mass. After a thorough parameter space scan, we identify promising points for gravitational wave production. We then study the resulting gravitational wave energy density for this set of points, and we observe that the gravitational waves should be observable in the next generation of both space-based and ground-based interferometers. Finally, we show how the presence of the Polonyi term can be used to further boost the gravitational wave energy density, which is correlated with the gravitino mass.