Redshift drift constraints on holographic dark energy

TL;DR

The paper investigates how the Sandage-Loeb test can improve constraints on holographic dark energy models by breaking parameter degeneracies and enhancing precision in key cosmological parameters over a 30-year observational period.

Contribution

It demonstrates the effectiveness of the SL test in tightening constraints on holographic dark energy models using simulated data, filling gaps in current observational capabilities.

Findings

SL test breaks degeneracy between $\

and

improves parameter constraints significantly over 30 years,

Abstract

The Sandage-Loeb (SL) test is a promising method for probing dark energy because it measures the redshift drift in the spectra of Lyman-$\alpha$ forest of distant quasars, covering the "redshift desert" of $2\lesssim z\lesssim5$, which is not covered by existing cosmological observations. Therefore, it could provide an important supplement to current cosmological observations. In this paper, we explore the impact of SL test on the precision of cosmological constraints for two typical holographic dark energy models, i.e., the original holographic dark energy (HDE) model and the Ricci holographic dark energy (RDE) model. To avoid data inconsistency, we use the best-fit models based on current combined observational data as the fiducial models to simulate 30 mock SL test data. The results show that SL test can effectively break the existing strong degeneracy between the present-day matter density $\Omega_{m0}$ and the Hubble constant $H_0$ in other cosmological observations. For the considered two typical dark energy models, not only can a 30-year observation of SL test improve the constraint precision of $\Omega_{m0}$ and $h$ dramatically, but can also enhance the constraint precision of the model parameters $c$ and $\alpha$ significantly.