Modified holographic Ricci dark energy coupled to interacting dark matter and a non interacting baryonic component

TL;DR

This paper investigates a modified holographic Ricci dark energy model coupled with interacting dark matter and a non-interacting baryonic component, showing it resolves the cosmic-age problem and aligns with early universe constraints.

Contribution

It introduces a modified holographic Ricci dark energy model that is compatible with observational data and early universe bounds, improving upon previous holographic dark energy models.

Findings

The universe's age is estimated at 13.17 Gyr, avoiding the cosmic-age problem.

Dark energy at high redshift remains within bounds from nucleosynthesis and CMB data.

The model aligns with Planck and CMBPol bounds on early dark energy.

Abstract

We examine a Friedmann-Robertson-Walker universe filled with interacting dark matter, modified holographic Ricci dark energy (MHRDE), and a decoupled baryonic component.The estimations of the cosmic parameters with Hubble data lead to an age of the universe of $13.17 {\rm Gyr}$ and show that the MHRDE is free from the cosmic-age problem at low redshift ($0 \leq z \leq 2$) in contrast to holographic Ricci dark energy (HRDE) case. We constrain the parameters with the Union2 data set and contrast with the Hubble data. We also study the behavior of dark energy at early times by taking into account the severe bounds found at recombination era and/or at big bang nucleosynthesis. The inclusion of a non interacting baryonic matter forces that the amount of dark energy at $z_{t} \sim {\cal O}(1)$ changes abruptly implying that $\Omega_x (z\simeq 1100) =0.03$, so the bounds reported by the forecast of Planck and CMBPol experiments are more favored for the MHRDE model than in the case of HRDE cutoff. For the former model, we also obtain that at high redshift the fraction of dark energy varies from 0.006 to 0.002, then the amount of $\Omega_x $ at the big bang nucleosynthesis era does not disturb the observed Helium abundance in the universe provided that the bound $\Omega_{x}(z\simeq 10^{10})<0.21$ is hold.