Stringent constraint on the CCC+TL cosmology with $H(z)$ Measurements

Abstract

Recently, the Covarying Coupling Constants and Tired Light (CCC+TL) hybrid model was proposed to explain the unexpectedly small angular diameters of high-redshift galaxies observed by the James Webb Space Telescope (JWST) that are challenging to reconcile with the $\hat{I}›$CDM model. In this work, we test the CCC+TL model against model-independent Hubble parameter [$H(z)$] measurements obtained from cosmic chronometers. It turns out that the parameter set optimized for the type-Ia supernova (SN Ia) dataset within the CCC+TL model fails to reproduce the $H(z)$ data, but the $\hat{I}›$CDM model works well. Statistical comparison using the $\hat{I}”\ddot{I}{‡}^2$ strongly favors $\hat{I}›$CDM over CCC+TL for the $H(z)$ data, with $\hat{I}”\ddot{I}{‡}^2=61.52$. Crucially, the CCC+TL framework exhibits a severe internal tension, where the SN Ia-optimized speed-of-light variation index $\hat{I}\pm$ is rejected by the $H(z)$ dataset with a likelihood ratio of $R\approx 1.7\times 10^{-14}$. Our result suggests that the tension posed by JWST observations of compact high-$z$ galaxies may originate from the intrinsic properties and evolution of galaxies in the early universe.

Published in MNRAS, Volume 547, Issue 3, stag430

References in corpus (1)

• Comparative Analysis of EMCEE, Gaussian Process, and Masked Autoregressive Flow in Constraining the Hubble Constant Using Cosmic Chronometers Dataset

Cited by in corpus (3)

• Dark energy, spatial curvature, and star formation efficiency from JWST photometric and spectroscopic high-redshift galaxies
• New $H(z)$ measurement at Redshift = 0.12 with DESI Data Release 1
• Testing the CCC+TL cosmology with cosmic-chronometer measurements of the Hubble parameter