Small Deviations from Gaussianity and the Galaxy Cluster Abundance Evolution

In this paper, we raise the hypothesis that the density fluctuation field, which originates the growth of large-scale structures, is a combination of two or more distributions, instead of assuming that the observed distribution of matter stems from a single Gaussian field produced in the very early universe, as is widely accepted. By applying the statistical analysis of finite-mixture distributions to a specific combination of Gaussian plus non-Gaussian random fields, we studied the case in which just a small departure from Gaussianity is allowed. Our results suggest that even a very small level of non-Gaussianity may introduce significant changes in the cluster abundance evolution rate.