Dark Matter Freeze-Out via Catalyzed Annihilation

We present a new paradigm of dark matter freeze-out, where the annihilation of dark matter particles is catalyzed. We discuss in detail the regime in which the depletion of dark matter proceeds via 2 chi -> 2A' and 3A' -> 2 chi processes, where chi and A' denote dark matter and the catalyst, respectively. In this regime, the dark matter number density is depleted polynomially rather than exponentially (Boltzmann suppression) as in classical weakly interacting massive particles and strongly interacting massive particles. The paradigm applies for a secluded weakly interacting dark sector with dark matter in the MeV-TeV mass range. The catalyzed annihilation paradigm is compatible with cosmic microwave background and big bang nucleosynthesis constraints, with enhanced indirect detection signals.

Automated summary

The paper introduces a new paradigm of dark matter freeze-out, where the annihilation of dark matter particles is catalyzed, in a secluded weakly interacting dark sector. The depletion of dark matter proceeds via specific processes, resulting in polynomial depletion of dark matter number density, contrary to exponential depletion seen in classical weakly interacting and strongly interacting massive particles. This paradigm is compatible with cosmic microwave background and big bang nucleosynthesis constraints, with enhanced indirect detection signals.