Observable Signatures of No-Scale Supergravity in NANOGrav

TL;DR

This paper proposes that signatures of no-scale Supergravity, such as primordial black holes and gravitational waves, could be observed in NANOGrav data, linking quantum gravity theories with astrophysical observations.

Contribution

It introduces a novel connection between no-scale Supergravity models and observable gravitational wave signatures in NANOGrav data.

Findings

Primordial black holes formed from inflationary potentials in no-scale Supergravity.

Generation of primordial gravitational waves consistent with PTA data.

Early matter-dominated era before BBN caused by PBH evaporation.

Abstract

In light of NANOGrav data we provide for the first time possible observational signatures of Superstring theory. Firstly, we work with inflection-point inflationary potentials naturally realised within Wess-Zumino type no-scale Supergravity, which give rise to the formation of microscopic primordial black holes (PBHs) triggering an early matter-dominated era (eMD) and evaporating before Big Bang Nucleosythesis (BBN). Remarkably, we obtain an abundant production of primordial gravitational waves (PGW) at the frequency ranges of nHz, Hz and kHz and in strong agreement with Pulsar Time Array (PTA) GW data. This PGW background could serve as a compelling observational signature for the presence of quantum gravity via no-scale Supergravity.