Constraints on number and masses of neutrinos from cosmological data

In this seminar I will show how cosmology provides one of the best means to tackle the absolute scale of neutrino masses, as neutrinos can leave key signatures in several cosmological data sets. I will then show the achievable constraints on the number and the masses of the neutrinos, from current and future data, for both active and sterile species. Indeed, models with one ore more sterile, right-handed neutrinos emerged as an extension of the minimal three neutrino scheme as an explanation of some experiments concerning the neutrino oscillation phenomena.