First Simulations of Axion Minicluster Halos

Eggemeier, Benedikt; Redondo, Javier; Dolag, Klaus; Niemeyer, Jens C. und Vaquero, Alejandro (2020): First Simulations of Axion Minicluster Halos. In: Physical Review Letters, Bd. 125, Nr. 4, 041301

Abstract

We study the gravitational collapse of axion dark matter fluctuations in the postinflationary scenario, so-called axion miniclusters, with N-body simulations. Largely confirming theoretical expectations, overdensities begin to collapse in the radiation-dominated epoch and form an early distribution of miniclusters with masses up to 10(-12) M-circle dot. After matter-radiation equality, ongoing mergers give rise to a steep power-law distribution of minicluster halo masses. The density profiles of well-resolved halos are Navarro-Frenk-White-like to good approximation. The fraction of axion dark matter in these bound structures is similar to 0.75 at redshift z = 100.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0031-9007
• Sprache: Englisch