Testing Primordial Black Holes as Dark Matter in Supergravity from Gravitational Waves

TL;DR

This paper investigates how supergravity models can simultaneously explain inflation and primordial black holes as dark matter, predicting detectable gravitational wave signals for future space-based interferometers.

Contribution

It introduces a supergravity framework that naturally unifies inflation and PBH dark matter, and predicts observable gravitational wave signatures.

Findings

Efficient PBH formation compatible with observational constraints.

Predicted stochastic GW background detectable by future interferometers.

Supergravity models show predictive power in GW physics.

Abstract

We explore the Gravitational Waves (GW) phenomenology of a simple class of supergravity models that can explain and unify inflation and Primordial Black Holes (PBH) as Dark Matter (DM). Our (modified) supergravity models naturally lead to a two-field attractor-type double inflation, whose first stage is driven by Starobinsky scalaron and the second stage is driven by another scalar belonging to a supergravity multiplet. The PBHs formation in our supergravity models is efficient, compatible with all observational constraints, and predicts a stochastic GW background. We compute the PBH-induced GW power spectrum and show that GW signals can be detected within the sensitivity curves of the future space-based GW interferometers such as LISA, DECIGO, TAIJI and TianQin projects, thus showing predictive power of supergravity in GW physics and their compatibility.