Authors

Abstract

We provide a consistent framework to set limits on properties of light sterileneutrinos coupled to all three active neutrinos using a combination of the latest cosmologicaldata and terrestrial measurements from oscillations, -decay and neutrinoless double- decay(0) experiments. We directly constrain the full 3+1 active-sterile mixing matrix elements|U4|2, with 2 (e, , ), and the mass-squared splitting m241 m24 m21. We find thatresults for a 3+1 case differ from previously studied 1+1 scenarios where the sterile is onlycoupled to one of the neutrinos, which is largely explained by parameter space volume effects.Limits on the mass splitting and the mixing matrix elements are currently dominated by thecosmological data sets. The exact results are slightly prior dependent, but we reliably findall matrix elements to be constrained below |U4|2 . 103.Short-baseline neutrino oscillation hints in favor of eV-scale sterile neutrinos are in serious tension with these bounds, irrespective of prior assumptions. We also translate thebounds from the cosmological analysis into constraints on the parameters probed by laboratory searches, such as m or m, the effective mass parameters probed by -decay and 0searches, respectively. When allowing for mixing with a light sterile neutrino, cosmology leadsto upper bounds of m < 0.09 eV and m < 0.07 eV at 95% C.L, more stringent than thelimits from current laboratory experiments.