Speaker
Description
In this work, we revisit the problem of sterile neutrino thermalisation for MeV reheating temperatures with the full oscillation paradigm of the 3+1 scheme, extending the analysis that we recently carried out in the absence of sterile neutrinos. For the first time, we consider the effect of all mixing angles, fixing those exclusive of active neutrinos to the values obtained in global-fit analyses but leaving the three active-sterile angles as free parameters. The evolution of neutrinos is obtained with a modified version of the FortEPiaNO code and the bounds on active-sterile parameters and the reheating temperature are computed using the latest available cosmological data. In particular, we performed a joint analysis that combines constraints from Big Bang Nucleosynthesis, the Cosmic Microwave Background, and galaxy surveys, alongside separate investigations of these datasets and forecasts for next-generation experiments.