摘要：Weakly- and Feebly-Interacting Massive Particles (WIMPs and FIMPs) are among the best-motivated dark matter (DM) candidates. In this paper, we investigate the production of DM through the WIMP and FIMP mechanisms during inflationary reheating. We show that the details of the reheating, such as the inflaton potential and the reheating temperature, have a strong impact on the genesis of DM. The strong entropy injection caused by the inflaton decay has to be compensated by a reduction of the portal coupling in the case of WIMPs, or by an increase in the case of FIMPs. We pinpoint the smooth transition between the WIMP and the FIMP regimes in the case of low reheating temperature. As an example, we perform a full numerical analysis of the singlet-scalar DM model; however, our results are generic and adaptable to other particle DM candidates.Interestingly, in the singlet-scalar DM model with low-reheating temperature, regions favored by the FIMP mechanism are already being tested by direct detection experiments such as LZ and XENONnT.
个人简介：Nicolás Bernal received his Ph.D. from Sorbonne University in Paris. After postdoctoral appointments in Barcelona, Lisbon, Bonn and the ICTP-SAIFR in São Paulo, he became professor at Antonio Nariño University in Bogotá Colombia. Recently, he joined New York University Abu Dhabi as a Senior Research Scientist. Nicolás is interested in the phenomenology of the early Universe, and in particular in the phenomenology of Dark Matter.