First simulations of axion minicluster halos
Abstract
We study the gravitational collapse of axion dark matter fluctuations in the postinflationary scenario, socalled axion miniclusters, with Nbody simulations. Largely confirming theoretical expectations, overdensities begin to collapse in the radiationdominated epoch and form an early distribution of miniclusters with masses up to $10^{12}\,M_\odot$. After matterradiation equality, ongoing mergers give rise to a steep powerlaw distribution of minicluster halo masses. The density profiles of wellresolved halos are NFWlike to good approximation. The fraction of axion DM in these bound structures is $\sim 0.75$ at redshift $z=100$.
 Publication:

arXiv eprints
 Pub Date:
 November 2019
 arXiv:
 arXiv:1911.09417
 Bibcode:
 2019arXiv191109417E
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 8 pages, 6 figures