Narrow Results

Asymmetric dark matter models are based on the hypothesis that the present-day abundance of dark matter has the same origin as the abundance of ordinary or "visible" matter: an asymmetry in the number densities of particles and antiparticles. They are largely motivated by the observed similarity in the mass densities of dark and visible matter, with the former observed to be about five times the latter. This review discusses the construction of asymmetric dark matter models, summarizes cosmological and astrophysical bounds, and touches on direct detection prospects and collider signatures.

The core-cusp problem remains as one of the unresolved challenges between observation and simulations in the standard ΛCDM model for the formation of galaxies. Basically, the problem is that ΛCDM simulations predict that the center of galactic dark matter halos contain a steep power-law mass density profile. However, observations of dwarf galaxies in the Local Group reveal a density profile consistent with a nearly flat distribution of dark matter near the center. A number of solutions to this dilemma have been proposed. We summarize investigations the possibility that the dark matter particles themselves self interact and scatter. The scattering of dark matter particles then can smooth out their profile in high-density regions. We also summarize theoretical theoretical models as to how self- interacting dark matter may arise. We summarize our own implementation this form in simulations of self-interacting dark matter in models for galaxy formation and evolution. Constraints on self-interacting dark matter are then summarized.

Since the pioneering work of Tremaine&Gunn in 1979 to the present, many attempts have been presented to constrain the dark matter particle mass from the phase-space density evolution until the approximate point of virialization of dark matter halos. In particular, recent numerical simulations of the evolution of the phase-space density of dwarf spheroidal dark matter halos revealed a strong tension between the obtained particle mass bound and the lower limit of few keV from other astrophysical constraints. We propose a novel approach to calculate the phase-space density distribution in dwarf galaxies, to show that such a discrepancy disappear if the dark matter distribution possesses a core in which quantum statistical effects are important, as in the case of the dark matter profiles of keV fermions recently introduced by Ruffini, Argüelles and Rueda (2015).

We present the results of the EROS-2 search for microlensing of stars in the Magellanic clouds and in the Milky-Way plane. More than hundred million of stars were monitored over a period of about 7 years. Hundreds of microlensing candidates have been found in the galactic plane, but only one was found towards the subsample of bright –well measured– Magellanic stars. This result implies that massive compact halo objects (machos) in the mass range 10⁻⁷M⊙ < M < 5M⊙ are ruled out as a major component of the Milky Way Halo. The optical depth estimates and the event duration distributions comply with the simple standard Milky-Way model.