Constraints on dark radiation from cosmological probes

International audienceWe present joint constraints on the number of effective neutrino speciesN_eff and the sum of neutrino masses M_nu, based on a technique which exploitsthe full information contained in the one-dimensional Lyman-Alpha forest fluxpower spectrum, complemented by additional cosmological probes. In particular,we obtain N_eff=2.91(+0.21)(-0.22) (95% CL) and M_nu<0.15 eV (95% CL) when wecombine BOSS Lyman-Alpha forest data with CMB (Planck+ACT+SPT+WMAPpolarization) measurements, and N_eff=2.88(+0.20)(-0.20) (95% CL) and M_nu