Universal properties of Dark Matter halos

TL;DR

This paper explores the universal density-size relation of Dark Matter halos across scales, showing consistency with LambdaCDM simulations and providing an analytical understanding via the secondary infall model, aiding in testing alternative theories.

Contribution

It offers an analytical explanation for the universal properties of Dark Matter halos within LambdaCDM, enabling observational constraints on deviations and modifications.

Findings

LambdaCDM simulations align with observed universal relations.

Secondary infall model explains the universality analytically.

Provides a framework to test alternative gravity theories.

Abstract

We discuss the universal relation between density and size of observed Dark Matter halos that was recently shown to hold on a wide range of scales, from dwarf galaxies to galaxy clusters. Predictions of LambdaCDM N-body simulations are consistent with this relation. We demonstrate that this property of LambdaCDM can be understood analytically in the secondary infall model. Qualitative understanding given by this model provides a new way to predict which deviations from LambdaCDM or large-scale modifications of gravity can affect universal behavior and, therefore, to constrain them observationally.