Observational constraints on generic models of non-minimal curvature-matter coupling

TL;DR

This paper examines non-minimal curvature-matter coupling models in cosmology, constraining their parameters using observational data to understand their viability in explaining late-time cosmic acceleration.

Contribution

It introduces a specific non-minimal coupling framework, parameterizes it, and uses observational data to identify parameter regions consistent with cosmic evolution.

Findings

Identified parameter regions where models fit late-time cosmic data

Analyzed energy transfer features between curvature and matter sectors

Constrained coupling strength parameters using observational datasets

Abstract

We investigate two classes of non-minimally coupled curvature-matter models in the FLRW universe with a perfect fluid and analyze their cosmological implications using Supernova Ia, Observed Hubble Data, and Baryon Acoustic Oscillation measurements. Non-minimal coupling is introduced via an additional term $\int d^4x \sqrt{-g} \mathcal{G}({\cal L}_{m}) f_2(R)$ in the Einstein-Hilbert action. To obtain observational constraints, we use an exponential-type fluid-pressure profile $p = p_0e^{ak}$ characterized by the dimensionless parameter $k$ and parameterize $f_2(R)$ as $R^n$ with another dimensionless parameter $n$. Two additional parameters, $\alpha$ and $\beta$ in the functional form of $\mathcal{G}({\cal L}_{m})$ determine the coupling strength. We identify significant regions in the $(n, k)$-parameter space for fixed coupling strength values where non-minimally coupled models align with observed late-time cosmic evolution. Additionally, we explore and discuss features of energy transfer between the curvature and matter sectors using observational data.