Seminarium "Teoria cząstek elementarnych i kosmologia"

Dark sectors generically contain particles with self-interactions, e.g. non-Abelian gauge fields or scalar fields not protected by any symmetry. In various models, these play crucial roles: either as mediators to the visible sector or the dark matter itself. The production dynamics of self-interacting, so-called cannibal states will be the focus of the talk. In particular, I will discuss the impact of solving the full system of coupled Boltzmann equations for the number densities and temperatures of all involved states, and describe three simple but phenomenologically rich scenarios. Finally, I will present a new mechanism for making dark matter cool again — how self-interactions can alleviate the Lyman-alpha limits, allowing for lighter DM states than usually expected.