The S_(8)tension in light of updated redshift-space distortion data and PAge approximation

One of the most prominent challenges to the standard Lambda cold dark matter(ΛCDM) cosmology is the tension between the structure growth parameter S;constrained by the cosmic microwave background(CMB) data and the smaller one suggested by the cosmic shear data. Recent studies show that, for ΛCDM cosmology, redshift-space distortion(RSD) data also prefers a smaller S;that is ~ 2-3σ lower than the CMB value, but the result is sensitive to the cosmological model. In the present work we update the RSD constraint on S;with the most up-to-date RSD data set where the correlation between data points is properly taken into account. To reduce the model dependence, we add in our Monte Carlo Markov Chain calculation the most up-to-date data sets of Type Ia supernovae(SN) and baryon acoustic oscillations(BAO), whose correlation with RSD is also taken into account, to constrain the background geometry. For ΛCDM cosmology we find S_(8)= 0.812 ± 0.026, which is ~ 2σ larger than previous studies, and hence is consistent with the CMB constraint. By replacing ΛCDM with the parameterization based on cosmic Age(PAge), an almost model-independent description of the late universe, we find that the RSD + SN + BAO constraint on S;is insensitive to the cosmological model.