FRW cosmological models with cosmological constant in f( R, T) theory of gravity

In the present paper, we have generalized the behaviors of the transit-decelerating to accelerating FRW cosmological model in f(R, T) gravity theory, where R and T are Ricci scalar and trace of the energy–momentum tensor, respectively. The solution of the corresponding field equations is obtained by assuming a linear function of the Hubble parameter H (i.e., q = c 1 + c 2 H), which gives a time-dependent deceleration parameter [Formula: see text], where c 3 and c 2 are arbitrary integrating constants (Tiwari et al. Eur. Phys. J. Plus, 131, 447 (2016); Ibid. 132, 126 (2017)). There are two scenarios in which we explain the particular form of scale factor thus obtained: (i) by using the recent constraints from observational Hubble data (OHD) and joint light curves (JLA) data, which show a cosmic deceleration to acceleration and (ii) by using new constraints from supernovae type Ia union data, which show accelerating expansion of the universe (q < 0) throughout its evolution. We have observed that EoS parameter, energy density parameters, and important cosmological planes yield results compatible with the modern observational data. For the derived models, we have calculated various physical parameters as luminosity distance, distance modulus, and apparent magnitude versus redshift for both current supporting observations.