Constraints on the combined models with R2‑q inflation and viable f(R) dark energy

Abstract

We investigate the observational constraints on the modified gravity, which combines the R2‑q inflation with the power-law (exponential) type of the viable f(R) dark energy models. We discuss the difference between the combined model and R2‑q gravity in the inflationary epoch and obtain the constraints on the deviation power q as well as the parameters in f(R) by using the CosmoMC package. The allowed ranges of the spectral index and tensor-to-scalar ratio from the Planck data are highly restricted, resulting in q<2.66×10‑2 and 2.17×10‑2 for the power-law and exponential types of f(R) gravity, respectively.