Reconstructing cosmic acceleration from f(R) modified gravity

Abstract

A variant of the accelerating cosmology reconstruction program is developed for $f(R)$ gravity. Reconstruction schemes in terms of e-foldings and by using an auxiliary scalar field are developed. An example of a model with a transient phantom behavior without real matter is explicitly discussed in both schemes. Detailed comparison of the two schemes of reconstruction is presented. It seems to support physical non-equivalence of the two frames.