Particle Models and the Small-Scale Structure of Dark Matter
Abstract
The kinetic decoupling of weakly interacting massive particles (WIMPs) in the early universe sets a scale that can directly be translated into a small-scale cutoff in the spectrum of matter density fluctuations. The formalism presented here allows a precise description of the decoupling process and thus the determination of this scale to a high accuracy from the details of the underlying WIMP microphysics. With decoupling temperatures of several MeV to a few GeV, the smallest protohalos to be formed range between 10^{-11} and almost 10^{-3} solar masses -- a somewhat smaller range than what was found earlier using order-of-magnitude estimates for the decoupling temperature; for a given WIMP model, the actual cutoff mass is typically about a factor of 10 greater than derived in that way, though in some cases the difference may be as large as a factor of several 100. Observational consequences and prospects to probe this small-scale cutoff, which would provide a fascinating new window into the particle nature of dark matter, are discussed
Cite
@article{arxiv.0903.0189,
title = {Particle Models and the Small-Scale Structure of Dark Matter},
author = {Torsten Bringmann},
journal= {arXiv preprint arXiv:0903.0189},
year = {2014}
}
Comments
19 pages, 7 figures. Extended discussion, improved figures and corrected typos. Matches the published version (invited contribution to NJP Focus Issue on 'Dark Matter and Particle Physics')