Topical Seminar: Probing low-reheating scenarios with minimal freeze-in dark matter

por Prof. Óscar Zapata (Universidad de Antioquia, Medellín, Colombia)

miércoles 2 jul. 2025 15:00 → 16:00 Europe/Madrid

1001-Primera-1-1-1 - Paterna. Seminario (Universe)

The feebly-interacting massive particle (FIMP) paradigm offers an intriguing solution to the dark matter (DM) puzzle. In this framework, FIMPs are produced via the freeze-in mechanism through extremely weak interactions with the Standard Model (SM) plasma. The parameter space for freeze-in DM through a light dark photon, often called "minimal freeze-in DM," is currently being probed by direct detection experiments that measure electron and nuclear recoil. After reviewing the basics of freeze-in production, this talk explores how reheating dynamics after cosmic inflation affects DM production in the minimal freeze-in model, focusing on matter-domination and kination scenarios. While instantaneous reheating is often assumed, this simplification breaks down for reheating temperatures $T_{RH}$ comparable to or below the DM production scale. In such cases, the equation-of-state parameter of the inflaton and the scaling of the SM temperature during reheating become crucial. Low $T_{RH}$ scenarios necessitate stronger couplings between the dark and visible sector to reproduce the observed DM relic abundance, thereby enlarging the parameter space regions probed by current and future DM experiments.

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