Dissipation Mechanisms from Multi-level Dark Matter Scattering
Tata Institute of Fundamental Research, India
Self-interacting dark matter models are interesting to study for various purposes. In many such models the dark matter species has more than one state which are typically separated by small mass gaps. The presence of heavier excited states leads to the possibility of inelastic scattering when two dark matter particles collide with each other. The upscattered particles can decay back to the ground state emitting other lighter particles in the process. This gives rise to new dissipative phenomena which are important for halo dynamics. I shall discuss the physics of inelastic scattering in the context of a simple two-level dark matter model and talk about the effects of the dissipation mechanisms on dark matter halo structure and evolution.