Cosmological Neutrinos

In the framework of the standard cosmological model, large-scale structure observations imply neutrino mass limits in the range sum m_nu < 0.4-2.0 eV (95% CL), depending on the included data sets. Future observations will further improve these sensitivities and may well lead to a positive neutrino-mass detection. The measured neutrino oscillation parameters in conjunction with the big-bang nucleosynthesis constraint on the primoridal nu_e chemical potential exclude a significant deviation from the standard cosmological neutrino density. Therefore, large-scale structure limits on the hot dark matter fraction indeed translate directly into neutrino mass limits. While neutrinos with sub-eV masses are almost negligible for the cosmic dark matter inventory, they fit nicely with leptogenesis scenarios for creating the baryon asymmetry of the universe