Cosmological scenario in κ(R, T) gravity

In this paper, we investigate the cosmic acceleration and the behavior of dark energy (DE) in the structure of the recently proposed kappa(R,T) gravity theory [G. R. P. Teruel, kappa(R,T) gravity, Eur. Phys. J. C 78 (2018) 660]. In this study, we obtained some fascinating cosmological features that are coherent with observational evidences and the touchstone Lambda CDM model. To find the deterministic solution, we consider a periodic deceleration parameter q = -1 + mcos(kt), where m,k > 0 [M. Shen and L. Zhao, Oscillating quintom model with time periodic varying deceleration parameter, Chin. Phys. Lett. 31 (2014) 010401], which predicts the decelerating and accelerating phases of the universe. The Equation of State (EoS) parameter also supports the idea of DE, which is the dominant component and it is responsible for the universe's accelerated expansion. Here, we also construct cosmographic parameters, like, H, j, l, S, and studied their evolution in spatially flat kappa(R,T) gravity. We find that these observations are sufficient in comparison with the universe's physical and kinematic properties and also consistent with ongoing (OHD+JLA) observation. Next, we apply the geometric diagnostics, the state-finder (r,s) in kappa(R,T) gravity to discriminate from the Lambda CDM model. We found that our model lies in quintessence and the Chaplygin Gas region. Finally, the model approaches Lambda CDM at the present epoch of the universe.