How the Dark Energy Can Reconcile \textit{Planck} with Local Determination of the Hubble Constant

TL;DR

This paper explores how modeling dark energy with varying equations of state can resolve the discrepancy between local and Planck measurements of the Hubble constant, significantly improving fit quality.

Contribution

It introduces a redshift-binned dark energy model that reduces the tension in Hubble constant measurements by adjusting dark energy's equation of state at different redshifts.

Findings

Significant reduction in chi-square statistic by -6.76.

Dark energy equation of state at low redshift is close to -2.

Higher redshift dark energy remains consistent with a cosmological constant.

Abstract

We try to reconcile the tension between the local 2.4\% determination of Hubble constant and its global determination by $\textit{Planck}$ CMB data and BAO data through modeling the dark energy variously. We find that the chi-square is significantly reduced by $\Delta\chi^2_\text{all}=-6.76$ in the redshift-binned dark energy model where the $68\%$ limits of the equation of state of dark energy read $w(0\leq z\leq 0.1)=-1.958_{-0.508}^{+0.509}$, $w(0.1< z\leq 1.5)=-1.006_{-0.082}^{+0.092}$, and here $w(z>1.5)$ is fixed to $-1$.