2010/03/23 by Weike Xiao, Xiao, Weike, Xufen Wu +1
Physics and Astronomy · #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Particle physics theoretical and experimental studies #astro-ph.CO
paper · pdf · doi:10.48550/arxiv.1003.4346
6 pages
arxiv created 2015/11/19 · arxiv updated 2015/11/20
The particle mass used in cosmology N-body simulations is close to 108M\odot, which is about 1065 times larger than the GeV scale expected in particle physics. However, self-gravity interacting particle systems made up of different particles mass have different statistical and dynamical properties. Here we demonstrate that, due to this particle mass difference, the nowaday cosmology N-body simulations can have introduced an excessive core collapse process, especially for the low mass halos at high redshift. Such dynamical effect introduces an excessive cuspy center for these small halos, and it implies a possible connection to the so called "small scale crisis" for CDM models. Our results show that there exist a physical limit in cosmological simulations, by using about 103 particles to describe smallest halos, and we provide a simple suggestion based on it to relieve those effects from the bias.