Galactic halos in cosmology with long-range scalar DM interaction

TL;DR

This study uses cosmological N-body simulations to explore how long-range scalar dark matter interactions influence galaxy-sized halo properties, revealing earlier structure formation and altered halo characteristics.

Contribution

It introduces a modified cosmological model with scalar interactions in dark matter, analyzing their impact on halo formation and properties through detailed simulations.

Findings

Scalar interactions support the Island Universe picture.

Structure formation shifts to higher redshifts with these interactions.

Halo properties like density profiles and shapes are affected.

Abstract

Based on a set of cosmological N-body simulations we analyze properties of the dark matter haloes (DM) in a galaxy mass range ($10^{11} - 10^{13} h^{-1}M_{\odot}$) in modified $\lcdm$ cosmology with additional dynamically screened scalar interactions in DM sector. Our simulations show that scalar interactions support picture of the Island Universe. Rapid structure formation processes are shifted into higher redshifts resulting in a much smaller accretion and merging rates for galactic haloes at low redshifts. Finally, we present how this "fifth" force affects halo properties, like density profile, triaxiality, ellipticities and the spin parameter.