English

Bayesian Model Comparison of $R_h=ct$ versus $\Lambda$CDM using HII galaxy Hubble diagram

Cosmology and Nongalactic Astrophysics 2026-04-01 v1

Abstract

We complement a recent analysis comparing Rh=ctR_\mathrm{h}=ct with Λ\LambdaCDM/wwCDM using HII galaxies and giant extragalactic HII regions, by carrying out Bayesian model comparison. For this purpose, we calculate the Bayes factors for Rh=ctR_\mathrm{h}=ct compared to flat Λ\LambdaCDM/wwCDM using the same dataset. When we use uniform priors on cosmological parameters, we find that the Bayes factors are close to 1, implying that Rh=ctR_\mathrm{h}=ct is equally favored compared to Λ\LambdaCDM/wwCDM. However, when we use normal priors on cosmological parameters based on Planck cosmology, we find that Rh=ctR_\mathrm{h}=ct is strongly favored over flat Λ\LambdaCDM, while Rh=ctR_\mathrm{h}=ct is marginally favored over flat wwCDM.

Cite

@article{arxiv.2603.28019,
  title  = {Bayesian Model Comparison of $R_h=ct$ versus $\Lambda$CDM using HII galaxy Hubble diagram},
  author = {Yuva Himanshu Pallam and Shantanu Desai},
  journal= {arXiv preprint arXiv:2603.28019},
  year   = {2026}
}

Comments

9 pages, 3 figures. Accepted for publication in Physics Letters A

R2 v1 2026-07-01T11:43:25.390Z