Gravitational Waves From No-Scale Supergravity

TL;DR

This paper explores four models based on no-scale supergravity that predict gravitational waves potentially detectable by future space-based observatories, linking supergravity modifications to observable cosmological signals.

Contribution

It introduces four specific no-scale supergravity models with modified Kähler or superpotential, connecting theoretical supergravity frameworks to observable gravitational wave signals.

Findings

Models produce gravitational waves detectable by LISA, BBO, DECIGO.

All models yield Starobinsky-like scalar potentials.

Scalar power spectrum aligns with Planck constraints.

Abstract

In this paper we study four concrete models, based on no-scale supergravity with SU(2,1)/SU(2)$\times$ U(1) symmetry. We modify either the K\"ahler potential or the superpotential, which are related to the no-scale theory with this symmetry. In this scenario, the induced Gravitational Waves, are calculated to be detectable by the future space-based observations such as LISA, BBO and DECIGO. The models under study are interrelated, as they all yield the Starobinsky effective-like scalar potential in the unmodified case. We evaluate numerically the scalar power spectrum and the stochastic background of the Gravitational Waves, satisfying the observational Planck cosmological constraints for inflation.