Direct reconstruction of dynamical dark energy from observational Hubble parameter data

TL;DR

This paper demonstrates that current observational Hubble parameter data can effectively reconstruct the dark energy equation of state, providing valuable insights into cosmic acceleration, with improved precision achievable through simulated high-quality data.

Contribution

It is the first to systematically reconstruct $w(z)$ using Hubble parameter data via principal component analysis, highlighting its potential and limitations compared to supernova data.

Findings

Current Hubble data can reconstruct $w(z)$ within 10% at $z \\lesssim 1.5$

Simulated high-quality data can constrain models within 5% at certain redshifts

Hubble data, despite being scarcer and lower quality than supernova data, still offers valuable cosmological insights.

Abstract

Reconstructing the evolution history of the dark energy equation of state parameter $w(z)$ directly from observational data is highly valuable in cosmology, since it contains substantial clues in understanding the nature of the accelerated expansion of the Universe. Many works have focused on reconstructing $w(z)$ using Type Ia supernova data, however, only a few studies pay attention to Hubble parameter data. In the present work, we explore the merit of Hubble parameter data and make an attempt to reconstruct $w(z)$ from them through the principle component analysis approach. We find that current Hubble parameter data perform well in reconstructing $w(z)$; though, when compared to supernova data, the data are scant and their quality is worse. Both $\Lambda$CDM and evolving $w(z)$ models can be constrained within $10\%$ at redshifts $z \lesssim 1.5$ and even $5\%$ at redshifts 0.1 $\lesssim$ z $\lesssim$ 1 by using simulated $H(z)$ data of observational quality.