Co-Decaying Dark Matter
I will discuss a recently proposed mechanism for thermal dark matter freezeout, termed Co-Decaying Dark Matter. Multi-component dark sectors with degenerate particles and out-of-equilibrium decays can co-decay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles, rather than from Boltzmann suppression. Several models that realizes co-decaying dark matter will be presented. A generic prediction of this framework is an early dark matter dominated phase in the history of the universe, that results in the enhanced growth of dark matter perturbations on small scales, which could appear as compact micro-halos today. The framework can lead to significant boost factors for indirect detection experiments, such as FERMI, where dark matter would appear as point sources.