New constraints on the reheating temperature of the universe after WMAP-5

We report new constraints on the reheating temperature of the universe by analyzing the recent cosmic microwave background (CMB) data from the WMAP five year survey. From WMAP-5 data alone we found an upper limit at 95% c.l. of T-rh > 2 MeV, while including external priors from the SDSS red luminous galaxy survey and age constraints improves the limit to T-rh > 3.2 MeV (again at 95% c.l.). Future analysis from combined CMB and weak lensing surveys as Planck and DUNE will improve the the constraints by a factor similar to 2. We test the stability of the current upper limits on neutrino masses from cosmology under the hypothesis of non-standard thermal neutrino background. (C) 2008 Elsevier B.V. All rights reserved.