p-wave Dark Matter Constraints from the Extragalactic gamma-Ray Background

Dark matter (DM) non-gravitational characterization is a long enduring quest in modern physics. In this thesis, constraints on the p-wave phase-space average annihilation cross section of DM are posited. This is done by considering a velocity dependent self-annihilation cross section, combined with a Maxwellian approximation for its phase-space average in a halo. This approximation requires knowledge of the 3-dimensional velocity dispersion of the DM in the halo, which is self-consistently derived via the Eddington inversion theory. Finally, this is applied to calculate the predicted flux of gamma-rays from the isotropic gamma-ray background (IGRB). Constraints on the p-wave phase-space average annihilation cross section for a range of DM particle masses are then obtained by using Fermi-LAT IGRB data.