Status of σ<inf>8</inf> Tension in Different Cosmological Models

Λ CDM model provides the most plausible theoretical framework for our Universe. However, there are some drawbacks within this model, one of them is the σ8 tension between CMB and LSS observations. We study two models, namely, Hu-Sawicki Model (HS) and Chavallier-Polarski-Linder (CPL) parametrization of dynamical dark energy (DDE). We found that σ8 tension increases in HS model whereas it is somewhat alleviated in DDE model. Recently, it has also been shown that viscosity in dark matter can resolve this tension. Modified cosmological models change the matter power spectrum which also depends upon the neutrino mass. As massive neutrinos suppress the matter power spectrum on the small length scales, bounds on neutrino mass also get modified in these models.