title: Universal properties of dark matter halos.
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 cold dark matter (ΛCDM) N-body simulations are consistent with this relation. We demonstrate that this property of ΛCDM can be understood analytically in the secondary infall model. Qualitative understanding given by this model provides a new way to predict which deviations from ΛCDM or large-scale modifications of gravity can affect universal behavior and, therefore, to constrain them observationally.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, FSB/ITP/LPPC, BSP 720, CH-1015, Lausanne, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Boyarsky
authors.forename: A
authors.initials: A
authors.lastname: Neronov
authors.forename: O
authors.initials: O
authors.lastname: Ruchayskiy
authors.forename: I
authors.initials: I
authors.lastname: Tkachev