Dark Matter Particles & Distribution

One of the biggest challenges to modern cosmology and astrophysics is the understanding of how galaxies and clusters of galaxies formed and evolved. In the context of general relativity, it is well known that observations of the large-scale structure of the Universe cannot be explained without assuming the existence of a dark matter component that can be classified, according to its characteristic free-streaming length, into hot (with the particle’s mass on the eV scale); warm (with the mass on the keV scale) and, finally, cold (with mass on the GeV scale). Only cold dark matter (CDM) is able to account for the observed large-scale structure of the Universe. Thus, the CDM paradigm has become one of the fundamental pillars of the standard cosmological model. Although the existence of dark matter is observationally well-established, its nature and particle properties are still unknown. Over the last decades, cosmological N-body simulations have increased their resolution, allowing the internal structure of CDM halos on small scales to be resolved. Thus, several challenges for the CDM paradigm emerged [1, 2,3]. First, there is the “cuspy-core problem”: N-body simulations predicted that the central density increases, while observations of dark matter-dominated systems, such as low surface brightness (LSB) galaxies and dwarf spheroidal (dSph) galaxies, suggest a constant density profile in the innermost regions of the halos. Second, there is the ”missing satellite problem”: simulations predict an overabundance of substructures within the dark matter halos compared with high-resolution observations. Third, there is the “too-big-to-fail” problem: Milky Way satellites are not massive enough to be consistent with CMD predictions. Many possible solutions to the above issues have been proposed. Among them a new paradigm according to which DM would be formed by ultra-light particles that naturally arise in String Theory [4,5,6].

In the area of Dark Matter, I have been investigating the following topics:

• Dark Matter Distribution - forecast

• wave-Dark Matter

• modified gravity