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-α 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% confidence limit (C.L.) bound on the sum of neutrino masses is eV (95% C.L.), a bound which we believe to be robust. In the more often used constrained analysis with N ν = 3, w = −1, and α s = 0, we find a bound of 0.48 eV without using the Lyman-α data. If the Lyman-α data are used, the bound shrinks to eV (95% C.L.), depending strongly on the Lyman-α analysis used. Finally, we have also calculated how the effective A -parameter used in the SDSS BAO analyses changes under the influence of a non-zero neutrino mass. We find that A = 0.469( n /0.98) −0.35 (1+0.94Ω ν /Ω m ) ± 0.017.