Speaker: Ouynh Lan Nguyen (Notre Dame)

Abstract: The small scale structure problems remains a challenging discrepancy between observations and simulations in the standard LambdaCDM model for the formation of galaxies. The problem is that LambdaCDM simulations predict a steep power-law mass density profile at the center of galactic dark matter halos. 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. Here, we summarize investigations into the possibility that the dark matter particles themselves self interact and scatter. Such self-interacting dark matter particles can smooth out the dark-matter profile in high-density regions. In this talk, we will present the beyond standard model for MeV dark matter and its constraint with the astrophysical observations. We also study the formation of the halo dark matter and its impact on properties of neutron stars included mass, gravitational mass, and tidal deformability.