The impact of the locally measured Hubble parameter on the mass of sterile neutrino

Abstract

ABSTRACT We present a precise analysis to test hypothetical models involving sterile neutrinos beyond the standard flat-ΛCDM cosmology with the CMB observations from the Planck mission and BAO measurements. This analysis shows that adding the locally measured Hubble parameter H0  = 73.00 ± 1.75 km s−1 Mpc−1 to the data removes the need for the informative physical $m_{\mathrm{ sterile}}^{\mathrm{ thermal}}$ prior in CMB constraints of $m_{\nu ,\mathrm{ sterile}}^{\mathrm{ eff}}$. Under the constraints from the data containing the locally measured H0 we obtain an upper limit $m_{\nu ,\mathrm{ sterile}}^{\mathrm{ eff}} \lt 0.306$ eV scale mass for the massive sterile neutrino, and an upper limit Σmν < 0.214 eV scale mass for the three degenerate massive neutrino (95 per cent confidence level). We also obtain the value σ8  = $0.81^{+0.05}_{-0.06}$ (95 per cent confidence level), which is in compatibility with the constraints from Planck 2015 CMB data at the 1σ level. We find that introducing parameter $m_{\nu ,\mathrm{ sterile}}^{\mathrm{ eff}}$ to the model of cosmology reduces the σ8 value and moves it closer to the obtained value for this parameter from the KiDS-450 analysis. Our results show that the locally measured Hubble parameter can increase constraints on σ8 values.