DE models with combined $H_0 \cdot r_d $ from BAO and CMB dataset and friends

TL;DR

This study investigates dynamical dark energy models using a combined parameter from BAO and CMB data to address the Hubble tension, finding only the Low correlation (LC) model fits Planck constraints well.

Contribution

It introduces a novel approach of using the product of H_0 and r_d as a single parameter to analyze multiple dark energy models with combined BAO and CMB data.

Findings

Only the LC model fits Planck 2018 constraints with large error margins.

Most models fail to satisfy both H_0 and r_d constraints simultaneously.

Lambda CDM remains statistically preferred.

Abstract

It has been theorized that Dynamical Dark Energy (DDE) could be a possible solution to the Hubble tension. To avoid the degeneracy between the Hubble parameter $H_0$ and the sound horizon scale $r_d$, in this article we use their multiplication as one parameter $c/\left(H_0 r_d\right)$ and we use it to infer cosmological parameters for 6 different models - $\Lambda$CDM and 5 DDE parametrizations -- the Chevallier-Polarski-Linder (CPL), the Barboza-Alcaniz (BA), the Low correlation (LC), the Jassal-Bagla-Padmanabhan (JBP) and the Feng-Shen-Li-Li model. We choose a dataset that treats this combination as one parameter, that includes the Baryon Acoustic Oscillation (BAO) data $0.11 \le z \le 2.40$ and additional points from the Cosmic Microwave Background (CMB) Peaks ($z \approx 1090$). To them, we add the marginalized Pantehon dataset and GRB dataset. We see that the tension is moved from $H_0$ and $r_d$ to $c/\left(H_0 r_d\right)$ and $\Omega_m$. There is only one model that satisfies the Planck 2018 constraints on both parameters and this is LC with a huge error. The rest cannot fit into both constraints. $\Lambda$CDM is preferred with respect to the statistical measures.