Cosmological Evolution via Interacting/Non-Interacting Holographic Dark Energy Model for Curved FLRW Space-time in Rastall Gravity

TL;DR

This paper investigates cosmic evolution in curved FLRW space-time within Rastall gravity, analyzing interacting and non-interacting holographic dark energy models constrained by observational data, and finds the interacting model closely resembles the standard DM model.

Contribution

It introduces a detailed analysis of holographic dark energy models in Rastall gravity with curved space-time, including exact solutions and observational constraints.

Findings

Interacting model closely resembles DM.

Holographic models can describe accelerating cosmic evolution.

Constraints support the viability of the models.

Abstract

In this work, we explore the phenomenon of cosmic evolution using curved FLRW space-time bounded by apparent horizon with a specific holographic cut-off. To this end, we use the framework of Rastall gravity (RG) and universe is assumed to be consists of interacting/ non-interacting dark energy (DE) and dark matter (DM). In both scenarios, we evaluate exact solutions of the dynamical equations and constraint the holographic parameter $c^{2}(z)$ assuming a slowly varying function of red-shift during non-interacting model. For interacting model, we consider $c^{2}$ as a constant function of red-shift. Moreover, we analyze nature of the obtained results via deceleration parameter $(q)$, statefinder pair $(j,s)$ and $Om(z)$-diagnostic by constraining the involved model parameters using latest observational data. The graphical analysis showed that interacting model is very close to $\Lambda$ cold DM ($\Lambda$CDM) model as compared to non-interacting case. We conclude that this holographic proposal is enough to describe the cosmic evolution at an accelerating rate.