Possible indication for non-zero neutrino mass and additional neutrino
  species from cosmological observations
  The constraints on total neutrino mass and effective number of neutrino
species based on CMB anisotropy power spectrum, Hubble constant, baryon
acoustic oscillations and galaxy cluster mass function data are presented. It
is shown that the discrepancies between various cosmological data in Hubble
constant and density fluctuation amplitude, measured in standard LCDM
cosmological model, can be eliminated if more than standard effective number of
neutrino species and non-zero total neutrino mass are considered. This
extension of LCDM model appears to be \approx 3 \sigma\ significant when all
cosmological data are used. The model with approximately one additional
neutrino type, N_eff \approx 4, and with non-zero total neutrino mass, \approx
0.5 eV, provide the best fit to the data. In the model with only one massive
neutrino the upper limits on neutrino mass are slightly relaxed. It is shown
that these deviations from LCDM model appear mainly due to the usage of recent
data on the observations of baryon acoustic oscillations. Larger than standard
number of neutrino species is measured mainly due to the comparison of the BAO
data with direct measurements of Hubble constant, which was already noticed
earlier. As it is shown below, the data on galaxy cluster mass function in this
case give the measurement of non-zero neutrino mass.
