Modified holographic Ricci dark energy coupled to interacting relativistic and non-relativistic dark matter in the nonflat universe

TL;DR

This paper investigates a modified holographic Ricci dark energy model interacting with dark matter in a nonflat universe, analyzing its impact on cosmic acceleration, dark energy dominance, and the universe's transition stages.

Contribution

It introduces a coupled dark energy-dark matter model in a nonflat universe and explores its effects on cosmic evolution and acceleration phases.

Findings

The transition from deceleration to acceleration aligns with the $ m extLambda$CDM model.

Dark energy remains dominant from past to future.

Interaction strength and dark matter composition influence the universe's evolution.

Abstract

The modified holographic Ricci dark energy coupled to interacting relativistic and non-relativistic dark matter is considered in the nonflat Friedmann-Robertson-Walker universe. Through examining the deceleration parameter, one can find that the transition time of the Universe from decelerating to accelerating phase in the interacting holographic Ricci dark energy model is close to that in the $\Lambda$ cold dark matter model. The evolution of modified holographic Ricci dark energy's state parameter and the evolution of dark matter and dark energy's densities shows that the dark energy holds the dominant position from the near past to the future. By studying the statefinder diagnostic and the evolution of the total pressure, one can find that this model could explain the Universe's transition from the radiation to accelerating expansion stage through the dust stage. According to the $Om$ diagnostic, it is easy to find that when the interaction is weak and the proportion of relativistic dark matter in total dark matter is small, this model is phantom-like. Through our studying, we find the interaction and the relativistic dark matter's proportion all have great influence on the evolution of the Universe.