Constraints on the Holographic Dark Energy Model from Type Ia Supernovae, WMAP7, Baryon Acoustic Oscillation and Redshift-Space Distortion

TL;DR

This study constrains the holographic dark energy model using combined geometric and growth rate data from supernovae, CMB, BAO, and RSD, revealing parameter ranges that suggest a phantom-like universe but also allowing quintessence behavior.

Contribution

It provides the first joint constraints on holographic dark energy parameters using multiple observational probes with Markov Chain Monte Carlo analysis.

Findings

Best-fit parameter c ≈ 0.75 with uncertainties

Best-fit σ8 ≈ 0.76 with uncertainties

Current data favor a phantom-like dark energy but allow quintessence within 3σ

Abstract

In this paper, we use the joint measurement of geometry and growth rate from matter density perturbations to constrain the holographic dark energy model. The geometry measurement includes type Ia supernovae (SN Ia) Union2.1, full information of cosmic microwave background (CMB) from WMAP-7yr and baryon acoustic oscillation (BAO). For the growth rate of matter density perturbations, the results $f(z)\sigma_8(z)$ measured from the redshift-space distortion (RSD) in the galaxy power spectrum are employed. Via the Markov Chain Monte Carlo method, we try to constrain the model parameters space. The jointed constraint shows that $c=0.750_{- 0.0999- 0.173- 0.226}^{+ 0.0976+ 0.215+ 0.319}$ and $\sigma_8=0.763_{- 0.0465- 0.0826- 0.108}^{+ 0.0477+ 0.0910+ 0.120}$ with $1,2,3\sigma$ regions. After marginalizing the other irrelevant model parameters, we show the evolution of the equation of state of HDE with respect to the redshift $z$. Though the current cosmic data points favor a phantom like HDE Universe for the mean values of the model parameters in the future, it can behave like quintessence in $3\sigma$ regions.