Structure of Dark Matter Halos From Hierarchical Clustering: II. Universality and Self-Similarity in Cluster-Sized Halos

Abstract

We investigate the structure of the dark matter halo formed in three different cold dark matter scenarios. We performed N-body simulations of formation of 13 cluster-sized halos. In all runs, density cusps proportional to $r^{-1.5}$ developed at the center. This result was independent of the cosmological models we simulated. We could not reproduce the cusp shallower than $r^{-1.5}$, which was obtained in some of previous studies. We also found that in all runs the density structure evolves in a self-similar way, even in $Ω\ne 1$ universes. These results show that the formation of structural form is a process decoupled from a background cosmology.