Constraints on transition redshift utilizing the latest H(z) measurements and comments on the Hubble tension

TL;DR

This paper constrains the transition redshift using recent H(z) data and methods, revealing that methodology impacts results more than data, and suggests a link between the Hubble tension and a specific cosmic epoch.

Contribution

It provides a comprehensive analysis of how different methods and datasets influence transition redshift constraints and explores their relation to the Hubble tension.

Findings

Transition redshift mean value is 0.65 ± 0.16.

Method choice significantly affects redshift constraints.

The redshift coincides with the onset of H0 deviation from Planck values.

Abstract

The motivation of this paper is to obtain reliable constraints of transition redshift ($z_{ztr}$) and, in combination with the evolution of the Hubble constant ($H_{0}$) that could alleviate the Hubble tension, discuss the possible origin of the tension. Utilizing the latest H(z) measurements and different methods ($\Lambda$CDM model, Cosmography, and Gaussian process method), we investigated the impact of methodology and dataset on $z_{ztr}$ constraints, and find that the choice of method has a greater impact on $z_{tr}$ than the observations themselves. Through a statistical analysis of the $z_{ztr}$ constraints from 2004 to 2024, we find that total $z_{tr}$ constraints (2004$-$2024) can be well described by a Gaussian function with the mean value 0.65 and the standard deviation 0.16; that is, $\bar{z}_{tr}$(all) = 0.65 $\pm$ 0.16. And we confirmed that both dataset and methodology can indeed significantly affect the final constraints. The screened $z_{tr}$ constraints with free $H_{0}$ gives a new result $\bar{z}_{tr}$(free) = 0.64 $\pm$ 0.16. Coincidentally, the $z_{tr}$ results overlap with the initial moment of $H_{0}$ evolution ($H_{0}$ value starts to deviate from the Planck result). This may suggest that the Hubble tension might be closely related to this particular period in the evolution of the Universe.