Cosmological Evolution in f(R,T) theory with Collisional Matter

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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 contains, besides the 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 FRW equations the equation of continuity and obtain a differential equation of second order in $H(z)$, and solve it numerically for studying the evolution of the cosmological parameters.
• Two $f(R,T)$ models are considered and the results with collisional matter are compared with the ones of the $\Lambda$CDM model, and also with the model where there exists only non-collisional matter.
• The curves show that the models are acceptable because the values found for $w_{eff}$ are consistent with the observational data.