Hierarchy of N-point functions in the LCDM and ReBEL cosmologies

Abstract

In this work we investigate higher order statistics for the \(\lcdm\) and ReBEL scalar-interacting dark matter models by analyzing \(180\hmpc\) dark matter N-body simulation ensembles. The N-point correlation functions and the related hierarchical amplitudes, such as skewness and kurtosis, are computed using the Count-In-Cells method. Our studies demonstrate that the hierarchical amplitudes \(S_n\) of the scalar-interacting dark matter model significantly deviate from the values in the \(\lcdm\) cosmology on scales comparable and smaller then the screening length \(r_s\) of a given scalar-interacting model. The corresponding additional forces that enhance the total attractive force exerted on dark matter particles at galaxy scales lowers the values of the hierarchical amplitudes \(S_n\). We conclude that hypothetical additional exotic interactions in the dark matter sector should leave detectable markers in the higher-order correlation statistics of the density field. We focussed in detail on the redshift evolution of the dark matter field's skewness and kurtosis. From this investigation we find that the deviations from the canonical \(\lcdm\) model introduced by the presence of the ``fifth'' force attain a maximum value at redshifts \(0.5<z<2\). We therefore conclude that moderate redshift data are better suited for setting observational constraints on the investigated ReBEL models.