A cosmological model in f(G,T) gravity with time varying deceleration parameter.

Shukla, Bhupendra Kumar; Tiwari, Rishi Kumaras; Beesham, Aroonkumaras

The current study aims at investigating a modified theory of gravity called f (G , T) theory. Our focus is on a Gauss-Bonnet cosmological model that integrates a non-linear Gauss-Bonnet term and a linear trace term. We assume f (G , T) = γ G m 1 n T , where γ , m and n represent free parameters. To solve the field equations, we employ a specialized formulation of the deceleration parameter, represented as q = α − β H , where α and β are model parameters. Consequently, we determine the optimal values of the model parameters by aligning them with the latest observational datasets, including 57 data points from the Cosmic Chronometers datasets, Pantheon datasets, and BAO datasets. Furthermore, we analyze the physical behavior of the cosmographic parameters corresponding to the constrained values of the model parameters, as well as energy density and pressure. The evolution of the deceleration parameter predicts a transition from the decelerated to the accelerated phases of the universe. Importantly, our f (G , T) cosmological model effectively describes the observed cosmic acceleration in the late-time universe, eliminating the need to introduce an additional dark energy component in the field equations.

ACCELERATION (Mechanics); DARK energy; GRAVITY; FRIEDMANN equations; ENERGY density; CHRONOMETERS

Astrophysics & Space Science, 2023, Vol 368, Issue 10, p1

0004-640X

Academic Journal

10.1007/s10509-023-04234-x