Gravitational Dark Matter Production in Supergravity $\alpha$-Attractor Inflation

TL;DR

This paper investigates gravitational dark matter production during supergravity-based inflation, analyzing how model parameters influence DM abundance and reheating temperature, with implications for cosmological constraints.

Contribution

It provides a numerical analysis of gravitational particle production in supergravity $ ext{α}$-attractor inflation, highlighting the effects of supergravity corrections and parameter dependencies.

Findings

Supergravity corrections suppress GPP efficiency.

Reheating temperature for sufficient DM production ranges from 10^3 to 10^7 GeV.

Weaker isocurvature constraints compared to standard scenarios.

Abstract

We consider gravitational particle production (GPP) of dark matter (DM) under a supergravity framework, where the $\alpha$-attractor inflation model is used. The particle spectrum is computed numerically and the DM number density is obtained. We show how the DM mass, gravitino mass and inflation model parameters modify the results, and find the reheating temperature which leads to sufficient DM production. In our setup, supergravity corrections suppress the efficiency of GPP, and make the isocurvature constraint much weaker compared with the normal case. With tensor-to-scalar ratio ranging from $10^{-3}-10^{-4}$ and DM mass from $10^{-2} m_\phi - m_\phi$, the required reheating temperature should be around $10^3 \textrm{GeV} - 10^7 \textrm{GeV}$.