Cosmic evolution in the background of non-minimal coupling in $f(R,T,R_{\mu\nu}T^{\mu\nu})$ Gravity

TL;DR

This paper investigates cosmic evolution within a modified gravity framework involving non-minimal matter-geometry coupling, deriving field equations in FLRW spacetime and constraining model parameters using energy bounds aligned with observations.

Contribution

It formulates and analyzes the $f(R,T,Q)$ gravity model with non-minimal coupling, exploring its implications for cosmic evolution and constraining parameters with observational data.

Findings

Derived modified field equations in FLRW background.

Constrained model parameters using energy bounds and observations.

Explored cosmic eras based on equation of state.

Abstract

An accelerated expansion phase is being experienced by the universe due to the presence of an unknown energy component known as dark energy (DE). To find out the cosmic evolution scientists ever tried to modify Einstein's gravitational theory and its unexplored parts. We also look forward to address the same problem with a different approach based on interaction between matter and geometry. For this purpose we consider $f(R,T,Q)$ modified theory (where $R$ is the Ricci Scalar, $T$ is the trace of energy-momentum tensor (EMT) $T_{uv}$ and $Q=R_{uv}T^{uv}$ is interaction of EMT $T_{\mu\nu}$ and Ricci Tensor $R_{uv}$). We formulate modified field equations in the background of Friedmann-Lema$\hat{i}$tre-Robertson-Walker (FLRW) model which is defined as $ds^2=dt^2-a(t)^2(dx^2+dy^2+dz^2 )$, where $a(t)$ represents the scale factor. In this formalism energy density is found using covariant divergence of modified field equations. $\rho$ involves a contribution from non-minimal matter geometry coupling which helps to study different cosmic eras based on equation of state (EOS). Furthermore, we apply the energy bounds to constrain the model parameters establishing a pathway to discuss the cosmic evolution for best suitable parameters in accordance with recent observations.