The neutrino mass bound from WMAP 3 year data, the baryon acoustic peak, the SNLS supernovae and the Lyman-α forest

We have studied bounds on the neutrino mass using new data from the WMAP 3 year data, the Sloan Digital Sky Survey measurement of the baryon acoustic (BAO) peak, the Type Ia supernovae from SNLS, and the Lyman-alpha forest. We find that even in the most general models with a running spectral index where the number of neutrinos and the dark energy equation of state are allowed to vary, the 95% con.dence limit ( C. L.) bound on the sum of neutrino masses is Sigma m(v) <= 0.62 eV (95% C.L.), a bound which we believe to be robust. In the more often used constrained analysis with N-v = 3, w = -1, and alpha(s) = 0, we find a bound of 0.48 eV without using the Lyman-alpha data. If the Lyman-alpha data are used, the bound shrinks to Sigma m(v) = 0.2-0.4 eV (95% C. L.), depending strongly on the Lyman-alpha analysis used. Finally, we have also calculated how the effective A-parameter used in the SDSS BAO analyses changes under the influence of a nonzero neutrino mass. We find that A = 0.469(n/0.98)(-0.35)(1+0.94 Omega(v)/Omega(m))+/- 0.017.