Two-parametric f(R) dark energy model and some observational constraints

Abstract

A modified [Formula: see text] viable model is proposed that behaves asymptotically as [Formula: see text]CDM and satisfies cosmological and local gravity constraints. Apart from a mass scale that is a priori defined, the model contains only one additional parameter, which is determined by the current value of the matter density parameter [Formula: see text]. Under the chameleon mechanism the model satisfies the thin shell restrictions for local gravity systems without imposing additional restrictions on model parameters. Signals of scalar–tensor regime in the growth of matter perturbations, are present. Using the mass scale to determine the matter density parameter today, the remaining free parameter covers the whole range of values needed to test the model against the more stringent constraints arising at galactic and galactic cluster scales. The finite time singularity of the model was analyzed. A comparison was made with known models with the same number of parameters.