Limits on the neutrino mass from cosmology

We use measurements of luminosity-dependent galaxy bias at several different redshifts, SDSS at z = 0.05, DEEP2 at z = 1 and LBGs at z = 3.8, combined with WMAP five-year cosmic microwave background anisotropy data and SDSS Red Luminous Galaxy survey three-dimensional clustering power spectrum to put constraints on cosmological parameters. Fitting this combined dataset, we show that the luminosity-dependent bias data that probe the relation between halo bias and halo mass and its redshift evolution are very sensitive to sum of the neutrino masses: in particular we obtain the upper limit of ∑m ν<0.28 eV at the 95% confidence level for a ΛCDM+m ν model, with a σ8 equal to σ8 = 0.759±0.025 (1σ). When we allow the dark energy equation of state parameter w to vary we find w = -1.30±0.19 for a general wCDM+mν model with the 95% confidence level upper limit on the neutrino masses at ∑m ν<0.59 eV. The constraint on the dark energy equation of state further improves to w = -1.125±0.092 when using also ACBAR and supernovae Union data, in addition to above, with a prior on the Hubble constant from the Hubble Space Telescope. Finally, we have investigated the ability of future cosmic shear measurements, like those achievable with the proposed Euclid mission, to constrain differences in the mass of individual neutrino species. © 2010 American Institute of Physics.