Gravitino Dark Matter and Non-Gaussianity

TL;DR

This paper explores how gravitino dark matter interacts with non-Gaussian primordial fluctuations, finding that large local-type non-Gaussianity challenges its viability within the modulated reheating framework.

Contribution

It demonstrates the incompatibility of gravitino dark matter with large local non-Gaussianity in the context of modulated reheating, and discusses alternative scenarios.

Findings

Gravitino dark matter is disfavored with large local non-Gaussianity.

Modulated reheating generates significant non-Gaussianity affecting dark matter models.

Brief discussion on curvaton mechanism and other dark matter scenarios.

Abstract

We investigate density fluctuations in a scenario with gravitino dark matter in the framework of modulated reheating, which is known to generate large non-Gaussianity. We show that gravitino dark matter is disfavored if primordial fluctuations have large local-type non-Gaussianity in this framework. We also briefly discuss the case with the curvaton mechanism and some other possible dark matter scenarios.