Cosmic transit models in an extended gravity theory

Abstract

Abstract We have investigated some cosmic transit models in the framework of an extended gravity theory where the usual Ricci scalar in the gravitational action is replaced by a sum of the Ricci scalar and a term proportional to the trace of the energy momentum tensor. A hybrid scale factor is assumed to simulate the cosmic transit behaviour. The hybrid scale factor has two parameters that describe the behaviour of the model at an initial epoch and at a late epoch. The parameters of the hybrid scale factor have been constrained from the cosmic transit behaviour. Four different cosmic transit models have been constructed and are confronted with the observational Hubble parameter data. A cosmographic test for the cosmic transit models is conducted to assess their dynamical evolution. The effect of the model parameters on the cosmic dynamics has been investigated.