gravity models as alternatives to cosmic acceleration

This article presents cosmological models that arise in a subclass of [Formula omitted] gravity models, with different f(R) functions and fixed T-dependence. That is, the gravitational lagrangian is considered as [Formula omitted], with constant [Formula omitted]. Here R and T represent the Ricci scalar and trace of the stress-energy tensor, respectively. The modified gravitational field equations are obtained through the metric formalism for the Friedmann-Lemaître-Robertson-Walker metric with signature [Formula omitted]. We work with [Formula omitted], [Formula omitted] and [Formula omitted], with [Formula omitted] and n all free parameters, which lead to three different cosmological models for our Universe. For the choice of [Formula omitted], this reduces to widely discussed f(R) gravity models. This manuscript clearly describes the effects of adding the trace of the energy-momentum tensor in the f(R) lagrangian. The exact solution of the modified field equations are obtained under the hybrid expansion law. Also we present the Om diagnostic analysis for the discussed models.