Mixture of fluids in f(R, T) theory of gravity with cosmological constant Λ

We have examined a [Formula: see text] cosmological model with mixture of two fluids by assuming a special law of variation of Hubble parameter proposed by Berman [Nuovo Cimento B 74 (1983) 182–186] that yields constant deceleration parameter in LRS-Bianchi type-I space-time in [Formula: see text] theory of gravity, where [Formula: see text] is the Ricci scalar and [Formula: see text] is the trace of the energy–momentum tensor. In this paper, one of the fluids represents the matter content of the universe and the other fluid is the cosmic microwave background. We have used the form [Formula: see text] with [Formula: see text] and [Formula: see text], where [Formula: see text] is any arbitrary coupling constant of [Formula: see text] gravity. Such a selection of functional [Formula: see text] leads to general relativistic field equations with trace [Formula: see text]-dependent term of cosmological constant [Formula: see text]. To obtain the exact solutions of field equations we have considered the equation of state [Formula: see text]. The different anisotropic physical models such as dust, radiation, hard and Zeldovich models are explained, Statefinder and om diagnostic parameter are also discussed.