2002/07/31 by Georg G. Raffelt, G. G. Raffelt
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Cosmic neutrino background #Cosmic ray #Dark Matter and Cosmic Phenomena #Measurements of neutrino speed #Neutrino #Neutrino Physics Research #Neutrino oscillation #Particle physics #Physics #Solar neutrino #Solar neutrino problem #astro-ph
paper · pdf · doi:10.1016/s1387-6473(02)00239-7
published as New Astron.Rev. 46 (2002) 699-708 · Contribution to Dennis Sciama Memorial Volume of NAR, additional references and reference updates in revised version
arxiv created 2002/08/08 · openalex publication_date 2002/10/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The case for small neutrino mass differences from atmospheric and solar neutrino oscillation experiments has become compelling, but leaves the overall neutrino mass scale mnu undetermined. The most restrictive limit of mnu < 0.8 eV arises from the 2dF galaxy redshift survey in conjunction with the standard theory of cosmological structure formation. A relation between the hot dark matter fraction and mnu depends on the cosmic number density nnu of neutrinos. If solar neutrino oscillations indeed correspond to the favored large mixing angle MSW solution, then big-bang nucleosynthesis gives us a restrictive limit on all neutrino chemical potentials, removing the previous uncertainty of nnu. Therefore, a possible future measurement of mnu will directly establish the cosmic neutrino mass fraction Omeganu. Cosmological neutrinos with sub-eV masses can play an interesting role for producing the highest-energy cosmic rays (Z-burst scenario). Sub-eV masses also relate naturally to leptogenesis scenarios of the cosmic baryon asymmetry. Unfortunately, the time-of-flight dispersion of a galactic or local-group supernova neutrino burst is not sensitive in the sub-eV range.