Evolution of the dark matter halo in numerical models

Abstract

Cosmological numerical models well reproduce many properties of a large-scale structure; however, there are a number of disagreements between simulation results and observations. Two most important inconsistencies are (i) the “cusp problem”, i.e., simulations show that the density in the inner halo regions tends to infinity at the center, and (ii) the problem of the number of halos, i.e., simulations show that the number of halos with small masses is larger than the number of observed dwarf Galaxies by a factor of 5–10. This paper is devoted to the study of these problems using rich statistical data, which is done for the first time. An extensive model catalog of halos was analyzed. It was shown that even a large sample of model halos contains no halo without “cusp”. Further possible ways for solving these problems are also discussed.