Free streaming of warm wave dark matter in modified expansion histories

Fuente: arXiv
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Main Authors: Long, Andrew J., Venegas, Moira
Format: Preprint
Published: 2024
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author Long, Andrew J.
Venegas, Moira
author_facet Long, Andrew J.
Venegas, Moira
contents In models of warm dark matter, there is an appreciable population of high momentum particles in the early universe, which free stream out of primordial over/under densities, thereby prohibiting the growth of structure on small length scales. The distance that a dark matter particle travels without obstruction, known as the free streaming length, depends on the particle's mass and momentum, but also on the cosmological expansion rate. In this way, measurements of the linear matter power spectrum serve to probe warm dark matter as well as the cosmological expansion history. In this work, we focus on ultra-light wave wave dark matter (WWDM) characterized by a typical comoving momentum $q_\ast$ and mass $m$. We first derive constraints on the WWDM parameter space $(q_\ast, m)$ using Lyman-$α$ forest observations due to a combination of the free-streaming effect and the white-noise effect. We next assess how the free streaming of WWDM is affected by three modified expansion histories: early matter domination, early dark energy, and very early dark energy.
format Preprint
id arxiv_https___arxiv_org_abs_2412_14322
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Free streaming of warm wave dark matter in modified expansion histories
Long, Andrew J.
Venegas, Moira
Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
In models of warm dark matter, there is an appreciable population of high momentum particles in the early universe, which free stream out of primordial over/under densities, thereby prohibiting the growth of structure on small length scales. The distance that a dark matter particle travels without obstruction, known as the free streaming length, depends on the particle's mass and momentum, but also on the cosmological expansion rate. In this way, measurements of the linear matter power spectrum serve to probe warm dark matter as well as the cosmological expansion history. In this work, we focus on ultra-light wave wave dark matter (WWDM) characterized by a typical comoving momentum $q_\ast$ and mass $m$. We first derive constraints on the WWDM parameter space $(q_\ast, m)$ using Lyman-$α$ forest observations due to a combination of the free-streaming effect and the white-noise effect. We next assess how the free streaming of WWDM is affected by three modified expansion histories: early matter domination, early dark energy, and very early dark energy.
title Free streaming of warm wave dark matter in modified expansion histories
topic Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2412.14322