New cosmological upper limit

New cosmological upper limit on neutrino mass. Recent neutrino results imply that one or more of the three neutrino flavors (ν_e, ν _μ , ν _τ ) have some mass (see Physics Today, Physics Today 0031-9228 55 

 2002 13  July 2002, page 13 ). Considering the number of neutrinos loose in the universe, even a small mass means they will have significantly influenced the development of galaxies. Various physics experiments have established an upper limit of 3 eV for the ν_e and whopping upper limits in the MeV range for the ν _μ and ν _τ . Now, a worldwide collaboration of astronomers has looked at the distribution of 250 000 galaxies in the 2 Degree Field Galaxy Redshift Survey and measured large-scale structure statistics in the form of a power spectrum. They compared the data with calculated power spectra using a model that...