Cosmological evolution in f ( R , T ) theory with collisional matter

We study the evolution of the cosmological parameters, namely, the deceleration parameter q (z)and the parameter of effective equation of state in a Universe containing, besides ordinary matter and dark energy, a self-interacting (collisional) matter, in the generalized f (R,T) theory of gravity, where R and T are the curvature scalar and the trace of the energy-momentum tensor, respectively. We use the generalized Friedmann-Robertson-Walker equations and the equation of continuity and obtain a differential equation in H (z), and we solve it numerically for studying the evolution of the cosmological parameters. Two f (R,T) models are considered. The results with collisional matter are compared with the ones of the [Lambda] cold dark matter model, and also with the model where only noncollisional matter exists. The curves show that the models are acceptable because the values found for w sub(eff) are consistent with observed data.