ANALYTIC SOLUTION FOR MATTER DENSITY PERTURBATIONS IN A CLASS OF VIABLE COSMOLOGICAL f(R) MODELS

摘要

For a class of viable cosmological models in f(R) gravity in which deviation from the Einstein gravity decreases as an inverse power law of the Ricci scalar R for large R, an analytic solution for density perturbations in the matter component during the matterdominated stage is obtained in terms of hypergeometric functions. An analytical expression for the matter transfer function at scales much smaller than the present Hubble scale is also obtained.