We propose a novel mechanism for the production of dark matter (DM) from a thermal bath based on the idea that DM particles $��$ can transform heat bath particles $��: �����������$. For a small initial abundance of $��$, this leads to an exponential growth of the DM number density in close analogy to other familiar exponential growth processes in nature. We demonstrate that this mechanism complements freeze-in and freeze-out production in a generic way, opening new parameter space to explain the observed DM abundance, and we discuss observational prospects for such scenarios.

Physical review letters 127(19), 191802 (1-6) (2021). doi:10.1103/PhysRevLett.127.191802

Published by APS, College Park, Md.