A reconstruction of modified holographic Ricci dark energy in $f(R,T)$ gravity

TL;DR

This paper explores a modified holographic Ricci dark energy model within $f(R,T)$ gravity, analyzing its cosmic evolution, stability, and compatibility with observational data, revealing a quintessence-like behavior and a transition from matter to dark energy dominance.

Contribution

It introduces a reconstruction of MHRDE in $f(R,T)$ gravity with specific functional form, analyzing its dynamics, stability, and observational viability.

Findings

The EoS parameter approaches -1 but remains above, indicating quintessence-like behavior.

The universe transitions from deceleration to acceleration at redshift z≈0.2.

The model is classically stable based on the squared speed of sound.

Abstract

In this paper, we consider a recently proposed model of Dark Energy (DE) know as Modified Holographic Ricci DE (MHRDE) (which is function of the Hubble parameter and its first derivative with respect to the cosmic time $t$) in the light of the $f(R,T)$ model of modified gravity, considering the particular model $f(R,T) = \mu R + \nu T$, with $\mu$ and $\nu$ constants. The equation of state (EoS) parameter $\omega_{\Lambda}$ approaches but never reaches the value -1, implying a quintessence-like behavior of the model. The deceleration parameter $q$ passes from decelerated to accelerated phase at a redshift of $z\approx 0.2$, showing also a small dependence from the values of the parameters considered. Thanks to the statefinder diagnostic analysis, we observed that the $\Lambda$CDM phase for the considered model is attainable. We observed that the fractional energy densities for DE and DM $\Omega_{\Lambda}$ and $\Omega_m$ have, respectively, an increasing and a decreasing pattern with the evolution of the universe, indicating an evolution from matter to DE dominated universe. Finally, studying the squared speed of the sound $v_s^2$ for our model, we found that is classically stable.