Implications of an Extended Dark Energy Model with Massive Neutrinos

Recently there have been reports of finding a lower bound on the neutrino mass parameter (Sigma m(nu) ) when using the Atacama Cosmology Telescope (ACT) and SPTpol data; however, these bounds on the Sigma m(nu) are still weaker for most cases around the 1 sigma level. In this context, here in this work, we study the consequences of using an enlarged four parameter dynamical dark energy equation of state on the neutrino mass parameter as well as on the Hubble and S8 tensions. The four parameter dark energy equation of state incorporates a generic nonlinear monotonic evolution of the dark energy equation of state, where the four parameters are the early and the present value of the equation of state, the transition scale factor, and the sharpness of the transition. We report that with lensing-marginalized Planck + BAO + Pantheon and prior on absolute magnitude M-B, and KIDS/Viking S-8 prior, the model favors a nonzero value for the neutrino mass parameter at most at the 1 sigma level (Sigma m(nu) = 0.1847(-0.165)(+0.0698) eV). In this case this model also brings down the Hubble tension to a 2.5 sigma level and the S8 tension to a similar to 1.5 sigma level. This model also provides tighter constraints on the value of the dark energy equation of state at present epoch w(o) (w(0) = -0.9901(-0.0766)(+0.0561)) tb in comparison to the Chevalier-Polarski and Linder-like parameterization.