Dynamical dark energy after Planck CMB final release and $H_0$ tension

TL;DR

This paper evaluates various dynamical dark energy models using recent Planck CMB data, BAO measurements, and local $H_0$ observations, finding that while some models alleviate the $H_0$ tension, BAO data challenge their viability.

Contribution

It compares multiple dark energy models with updated data, performs Bayesian evidence analysis, and identifies the CPL model as the best fit despite BAO constraints.

Findings

All models are preferred over $\\Lambda$CDM based on Bayesian evidence.

The CPL model best alleviates the $H_0$ tension.

BAO data reintroduces the tension, challenging dynamical dark energy solutions.

Abstract

In this article we compare a variety of well known dynamical dark energy models using the cosmic microwave background measurements from the 2018 Planck legacy and 2015 Planck data releases, the baryon acoustic oscillations measurements and the local measurements of $H_0$ obtained by the SH0ES (Supernovae, $H_0$, for the Equation of State of Dark energy) collaboration analysing the Hubble Space Telescope data. We discuss the alleviation of $H_0$ tension, that is obtained at the price of a phantom-like dark energy equation of state. We perform a Bayesian evidence analysis to quantify the improvement of the fit, finding that all the dark energy models considered in this work are preferred against the $\Lambda$CDM scenario. Finally, among all the possibilities analyzed, the CPL model is the best one in fitting the data and solving the $H_0$ tension at the same time. However, unfortunately, this dynamical dark energy solution is not supported by the baryon acoustic oscillations (BAO) data, and the tension is restored when BAO data are included for all the models.