Cosmological evolution in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>R</mml:mi><mml:mo>,</mml:mo><mml:mi>T</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math>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 $\mathrm{\ensuremath{\Lambda}}$ 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 ${w}_{\text{eff}}$ are consistent with observed data.

Not yet translated