Dark Energy with Phantom Crossing and the $H_0$ tension

TL;DR

This paper explores phantom crossing in dark energy as a potential solution to the Hubble tension, using multiple cosmological data sets to confirm its occurrence and constrain related parameters.

Contribution

It demonstrates the consistency of phantom crossing in dark energy across various data combinations and provides updated constraints on H_0 and crossing scale factor.

Findings

Phantom crossing is confirmed at 95% confidence with CMB+BAO data.

The H_0 value is consistent with local measurements, around 71 km/s/Mpc.

The crossing occurs at a scale factor approximately 0.85.

Abstract

We investigate the possibility of phantom crossing in the dark energy sector and solution for the Hubble tension between early and late universe observations. We use robust combinations of different cosmological observations, namely the CMB, local measurement of Hubble constant ($H_0$), BAO and SnIa for this purpose. For a combination of CMB+BAO data which is related to early Universe physics, phantom crossing in the dark energy sector is confirmed at $95$\% confidence level and we obtain the constraint $H_0=71.0^{+2.9}_{-3.8}$ km/s/Mpc at 68\% confidence level which is in perfect agreement with the local measurement by Riess et al. We show that constraints from different combination of data are consistent with each other and all of them are consistent with phantom crossing in the dark energy sector. For the combination of all data considered, we obtain the constraint $H_0=70.25\pm 0.78$ km/s/Mpc at 68\% confidence level and the phantom crossing happening at the scale factor $a_m=0.851^{+0.048}_{-0.031}$ at 68\% confidence level.