Completely Dark Matter from Rapid-Turn Multifield Inflation

TL;DR

This paper investigates gravitational particle production in rapid-turn multifield inflation models, identifying conditions under which such models can produce sufficient spin-0 dark matter consistent with cosmological observations.

Contribution

It compares two rapid-turn inflation models, showing one can generate the observed dark matter relic abundance through gravitational production, aligning with cosmological constraints.

Findings

One model produces enough dark matter via gravitational production.

The other model fails to generate sufficient dark matter.

The viable model aligns with relic abundance and perturbation measurements.

Abstract

We study cosmological gravitational particle production as applied to "rapid-turn" models of inflation involving two scalar fields. We are interested in the production of massive spin-0 particles that only interact gravitationally and provide a candidate for the dark matter. Specifically, we study two models of rapid-turn multifield inflation, motivated in part by the de Sitter swampland conjecture, that are distinguished by the curvature of field space and the presence or absence of field space 'angular momentum' conservation. We find that one of these models leads to insufficient particle production and cannot explain the observed dark matter relic abundance. The second model is able to explain the origin of spin-0 dark matter via gravitational production, and we identify the relevant region of parameter space that is consistent with measurements of the dark-matter relic abundance, the dark-matter-photon isocurvature perturbations, and the spectrum of curvature perturbations that is probed by cosmological observations. Our work demonstrates the compatibility of the de Sitter swampland conjecture with completely dark matter.