A simple toy model for a unified picture of dark energy, dark matter, and inflation

A specific scale factor in Robertson-Walker metric with the prospect of giving the overall cosmic history in a unified picture roughly is considered. The corresponding energy-momentum tensor is identified as that of two scalar fields where one plays the roles of both inflaton and dark matter while the other accounts for dark energy. A preliminary phenomenological analysis gives an order of magnitude agreement with observational data. The resulting picture may be considered as a first step towards a single model for all epochs of cosmic evolution.