Can phantom transition at $z\sim 1$ restore the Cosmic concordance?

TL;DR

This paper investigates whether a transitional dark energy model with an equation of state changing around redshift 1 can resolve the tension among different cosmological measurements, especially between CMB, BAO, and SNe Ia data.

Contribution

It introduces a novel transitional dark energy model that can reconcile CMB and SNe Ia data, addressing the cosmic tension at redshift around 1.

Findings

TDE model can reconcile CMB and SNe Ia calibrated by $M_B$.

EoS transition occurs around redshift 1 in the model.

Inclusion of a local $M_B$ prior influences the EoS transition sign.

Abstract

The tension among inferences of Hubble constant ($H_0$) is found in a large array of datasets combinations. Modification to the late expansion history is the most direct solution to this discrepancy. In this work, we examine the viability of restoring the cosmological concordance with a novel version of transitional dark energy (TDE). The main anchors for the cosmic distance scale: cosmic microwave background (CMB) radiation, baryon acoustic oscillation (BAO), and Type Ia supernova (SNe Ia) calibrated by Cepheids form a "impossible trinity", i.e., it's plausible to reconcile with any two of the three but unlikely to accommodate them all. Particularly, the tension between BAO and the calibrated SNe Ia can not be reconciled within the scenarios of late dark energy. Nevertheless, our analysis suggests that the TDE model can reconcile with CMB and SNe Ia calibrated by its absolute magnitude ($M_{\rm{B}}$) when the equation of state (EoS) of DE transits around $z\sim1$. Meanwhile, we see a positive sign that the EoS transits with the inclusion of a local prior on $M_{\rm{B}}$, whereas the opposite is true without the $M_{\rm{B}}$ prior.