Davide Racco (ETC and University of Zurich)

Production mechanisms for Dark Matter: from freeze-in to gravitational production

Various production mechanisms for dark matter complement the well-motivated option of freeze-out. The freeze-in scenario is viable for very weakly-coupled particles, which can be looked for in terrestrial experiments. I will discuss how this mechanism is cosmologically viable with respect to the curvature perturbations that it produces on large scales. Another minimal and unavoidable production mechanism for any dark sector is gravitational production during inflation. Its abundance today is determined by the evolution of the dark sector and its interactions during the early Universe. I will discuss as a prototypical example a model of dark QED with a massive mediator, showing how various processes determine its cosmological evolution, and how the preferred parameter space complements the one predicted from freeze-in.