Bose-Einstein Condensation of Dark Matter Axions
High Energy Physics - Phenomenology
2009-11-06 v4 Cosmology and Nongalactic Astrophysics
Statistical Mechanics
Abstract
We show that cold dark matter axions thermalize and form a Bose-Einstein condensate. We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles.
Cite
@article{arxiv.0901.1106,
title = {Bose-Einstein Condensation of Dark Matter Axions},
author = {P. Sikivie and Q. Yang},
journal= {arXiv preprint arXiv:0901.1106},
year = {2009}
}
Comments
4 pages. Three typos are corrected. Version to be published by Physical Review Letters