Growth of linear matter perturbations and current observational constraints

Abstract

We discuss, using a recently proposed parametrization for the growth index of linear matter perturbations, the observational constraints on the wCDM model and the Dvali–Gabadadze–Porrati (DGP) model with all current growth factor data. We find that the wCDM model is allowed by the observations at the 1σ confidence level, while the DGP model is only consistent with observations at 2σ confidence level.