Cosmological imprints of non-thermalized dark matter

TL;DR

This paper investigates how non-thermalized dark matter affects the universe's structure formation, using cosmological data to constrain models involving freeze-in and superWIMP production mechanisms.

Contribution

It provides a detailed analysis of dark matter phase-space evolution and its cosmological signatures, integrating Lyman-alpha, BBN, and collider constraints within a specific particle physics model.

Findings

Lyman-alpha data constrains non-thermal dark matter models.

The interplay of cosmological and collider constraints narrows the viable parameter space.

The study highlights the importance of combined observational probes for dark matter properties.

Abstract

Non-thermalized dark matter is a cosmologically viable alternative to the widely studied weakly interacting massive particle. We study the evolution of the dark matter phase-space distributions arising from freeze-in and superWIMP production as well as the combination of both. Utilizing our implementation in CLASS, we investigate the cosmological imprints on the matter power spectrum, constrained by Lyman-$\alpha$ forest observations. For the explicit example of a colored $t$-channel mediator model, we explore the cosmologically allowed parameter space highlighting the interplay of Lyman-$\alpha$ constraints with those from Big Bang Nucleosynthesis and the LHC.