Updated bounds on sum of neutrino masses in various cosmological scenarios

We present strong bounds on the sum of three active neutrino masses (∑ mν) in various cosmological models. We use the following baseline datasets: CMB temperature data from Planck 2015, BAO measurements from SDSS-III BOSS DR12, the newly released SNe Ia dataset from Pantheon Sample, and a prior on the optical depth to reionization from 2016 Planck Intermediate results. We constrain cosmological parameters in Λ CDM model with 3 massive active neutrinos. For this Λ CDM+∑ mν model we find a upper bound of ∑ mν < 0.152 eV at 95$%$ C.L. Adding the high-l polarization data from Planck strengthens this bound to ∑ mν < 0.118 eV, which is very close to the minimum required mass of ∑ mν 0.1 eV for inverted hierarchy. This bound is reduced to ∑ mν < 0.110 eV when we also vary r, the tensor to scalar ratio (Λ CDM+r+∑ mν model), and add an additional dataset, BK14, the latest data released from the Bicep-Keck collaboration. This bound is further reduced to ∑ mν < 0.101 eV in a cosmology with non-phantom dynamical dark energy (w₀ wₐ CDM+∑ mν model with w(z)≥ -1 for all z). Considering the w₀ wₐ CDM+r+∑ mν model and adding the BK14 data again, the bound can be even further reduced to ∑ mν < 0.093 eV. For the w₀ wₐ CDM+∑ mν model without any constraint on $w(z)$, the bounds however relax to ∑ mν < 0.276 eV. Adding a prior on the Hubble constant (H₀ = 73.24± 1.74 km/sec/Mpc) from Hubble Space Telescope (HST), the above mentioned bounds further improve to ∑ mν < 0.117 eV, 0.091 eV, 0.085 eV, 0.082 eV, 0.078 eV and 0.247 eV respectively. This substantial improvement is mostly driven by a more than 3σ tension between Planck 2015 and HST measurements of H₀ and should be taken cautiously. (abstract abridged)