Are Halos of Collisionless Cold Dark Matter Collisionless?

2004/03/31 by Chung-Pei Ma, Chung‐Pei Ma, Michael Boylan-Kolchin · 2 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph #hep-ph

paper · pdf · doi:10.1103/physrevlett.93.021301

published as Phys.Rev.Lett. 93 (2004) 021301 · 4 pages, 3 figures. Phys Rev Lett, in press on May 14

arxiv created 2004/06/24 · openalex publication_date 2004/07/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We study whether gravitational scattering of halo dark matter particles by subhalos can connect two seemingly independent problems: the abundance of subhalos in dark matter halos and the cuspiness of the halos' inner density profiles. Our numerical experiments indicate that subhalos can cause the collisionless dark matter particles in the centers of main halos to diffuse. Combined with tidal mass loss of the subhalos, this process introduces significant scatter in the inner density profiles and offers an explanation for the range of profiles seen in both observations and cosmological simulations.

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