Modified f(R) gravity consistent with realistic cosmology: from matter dominated epoch to dark energy universe

TL;DR

This paper presents a method to reconstruct modified f(R) gravity models that can replicate realistic cosmological evolution from matter domination to dark energy acceleration, compatible with Solar System tests.

Contribution

It introduces a general scheme for f(R) gravity reconstruction from any realistic FRW cosmology, including models that unify matter and dark energy epochs.

Findings

Models can reproduce matter-dominated and accelerated phases.

Some models align with WMAP data.

Unification of cosmological epochs possible with simple modifications.

Abstract

We develop the general scheme for modified $f(R)$ gravity reconstruction from any realistic FRW cosmology. We formulate several versions of modified gravity compatible with Solar System tests where the following sequence of cosmological epochs occurs: a. matter dominated phase (with or without usual matter), transition from decceleration to acceleration, accelerating epoch consistent with recent WMAP data b. $\Lambda$CDM cosmology without cosmological constant. As a rule, such modified gravities are expressed implicitly (in terms of special functions) with late-time asymptotics of known type (for instance, the model with negative and positive powers of curvature). In the alternative approach, it is demonstrated that even simple versions of modified gravity may lead to the unification of matter dominated and accelerated phases at the price of the introduction of compensating dark energy.