Cosmology with variable $G$ and nonlinear electrodynamics

TL;DR

This paper explores a cosmological model where the gravitational constant varies with cosmic time within a nonlinear electrodynamics framework, analyzing the universe's evolution and stability of the model.

Contribution

It introduces a novel cosmological model with a variable G dependent on the scale factor, incorporating nonlinear electrodynamics and stability analysis.

Findings

The model describes the evolution of the scale factor with a variable G.

Stability of the model is confirmed via the speed of sound analysis.

The impact of nonlinear electrodynamics parameter α on cosmic evolution.

Abstract

In a bid to resolve lingering problems in cosmology, more focus is being tilted towards cosmological models in which physical constants of nature are not necessarily real constants but vary with cosmic time. In this paper, we study a cosmological model in nonlinear electrodynamics with Newton's gravitational constant $G$, which is not a constant but varies in terms of a power law of the scale factor of the universe. Hence, the evolution of the scale factor $a(t)$ is studied in this model, which depends on a fine-tuning term of nonlinear electrodynamics, $\alpha$. Finally, we verify the stability of the model using the speed of sound.