Cosmological models with a hybrid scale factor in an extended gravity theory

A general formalism to investigate Bianchi type [Formula: see text] universes is developed in an extended theory of gravity. A minimally coupled geometry and matter field is considered with a rescaled function of [Formula: see text] substituted in place of the Ricci scalar R in the geometrical action. Dynamical aspects of the models are discussed by using a hybrid scale factor (HSF) that behaves as power law in an initial epoch and as an exponential form at late epoch. The power law behavior and the exponential behavior appear as two extreme cases of the present model.