Small Deviations from Gaussianity and The Galaxy Cluster Abundance Evolution

In this work, we raise the hypothesis that the density fluctuations field which originates the growth of large scale structures is a combination of two or more distributions, instead of assuming the widely accepted idea that the observed distribution of matter stems from a single Gaussian field produced in the very early universe. By applying the statistical analysis of finite mixture distributions to a specific combination of Gaussian plus non-Gaussian random fields, we studied the case where 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. Subject headings: Cosmology: large-scale structure of the universe – cosmology: theory — galaxies: clusters