Dark Energy Constraints after Planck

TL;DR

This paper analyzes Planck data within dark energy models to address the Hubble tension, finding that models with $w eq -1$ can reconcile the discrepancy and slightly favor Quintom dark energy.

Contribution

It provides a comprehensive analysis of dark energy models using Planck and supernova data, highlighting the potential of $w eq -1$ models to resolve the Hubble tension.

Findings

Planck data favor $w < -1$ when combined with SNLS.

Derived $H_0$ value aligns with direct measurements.

Current data slightly favor Quintom dark energy.

Abstract

The Planck collaboration has recently published maps of the Cosmic Microwave Background radiation with the highest precision. In the standard flat $\Lambda$CDM framework, Planck data show that the Hubble constant $H_0$ is in tension with that measured by the several direct probes on $H_0$. In this paper, we perform a global analysis from the current observational data in the general dark energy models and find that resolving this tension on $H_0$ requires the dark energy model with its equation of state (EoS) $w\neq-1$. Firstly, assuming the $w$ to be a constant, the Planck data favor $w < -1$ at about $2\,\sigma$ confidence level when combining with the supernovae "SNLS" compilation. And consequently the value derived on $H_0$, $H_0=71.3\pm2.0$ ${\rm km\,s^{-1}\,Mpc^{-1}}$ (68% C.L.), is consistent with that from direct $H_0$ probes. We then investigate the dark energy model with a time-evolving $w$, and obtain the 68% C.L. constraints $w_0=-0.81\pm0.19$ and $w_a=-1.9\pm1.1$ from the Planck data and the "SNLS" compilation. Current data still slightly favor the Quintom dark energy scenario with EoS across the cosmological constant boundary $w\equiv-1$.