Observational constraints and cosmological implications of NLE model with variable G
Centre for Interdisciplinary Mathematical Sciences, Institute of Science Banaras Hindu University, 221005, Varanasi, U.P, India
2 Centre for Cosmology, Astrophysics and Space Science, GLA University, 281406, Mathura, U.P, India
Accepted: 5 November 2022
Published online: 15 November 2022
We explore the cosmic dynamics of a homogeneous and isotropic cosmological model having flat spatial section driven by nonlinear electrodynamics (NLE) with the Newtonian constant G considered to be varying with the scale factor of the universe. By considering NLE field as the source of gravitation, we investigate for the current accelerated evolution of the universe. The evolution of universe starts with the nonzero energy density, then expands through a radiation dominated phase followed by a deceleration at the matter dominated phase and ends by transiting into the accelerating expansion during the recent past. We constrain the model parameters with the Observational Hubble Data to find the best-fit values of the parameters. By using the constrained values of parameters, we study the behavior of cosmological parameters like deceleration parameter, equation of state parameter along with the behavior of energy density, pressure and energy conditions. The classical stability of model is verified by using the adiabatic speed of sound squared. We end by utilizing diagnostic tools like statefinders and Om-diagnostic to examine the dark energy evolution in the model. We find that the NLE model with variable G explains the current accelerated expansion of the universe. However, the model does not incorporate the radiation dominated phase for the best-fit values of the parameters.
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