English

Can the angular scale of cosmic homogeneity be used as a cosmological test?

Cosmology and Nongalactic Astrophysics 2025-10-09 v2 General Relativity and Quantum Cosmology

Abstract

In standard cosmology, the cosmic homogeneity scale is the transition scale above which the patterns arising from non-uniformities -- such as groups and clusters of galaxies, voids, and filaments -- become indistinguishable from a random distribution of sources. Recently, different groups have investigated the feasibility of using such a scale as a cosmological test and arrived at different conclusions. In this paper, we complement and extend these studies by exploring the evolution of the spatial (RH{\cal{R}}_H) and angular (θH\theta_H) homogeneity scales with redshift, assuming a spatially flat, Λ\Lambda-Cold Dark Matter %(Λ\LambdaCDM) universe and linear cosmological perturbation theory. We confirm previous results concerning the non-monotonicity of RH{\cal{R}}_H with the matter density parameter Ωm0\Omega_{m0} but also show that it exhibits a monotonical behavior with the Hubble constant H0H_0 within a large redshift interval. More importantly, we find that, for z0.6z \gtrsim 0.6, the angular homogeneity scale not only presents a monotonical behavior with Ωm0\Omega_{m0} and H0H_0 but is quite sensitive to H0H_0, especially at higher redshifts. These results, therefore, raise the possibility of using θH\theta_H as a new, model-independent way to constrain cosmological parameters.

Keywords

Cite

@article{arxiv.2309.07263,
  title  = {Can the angular scale of cosmic homogeneity be used as a cosmological test?},
  author = {Xiaoyun Shao and Rodrigo S. Gonçalves and Carlos A. P. Bengaly and Uendert Andrade and Gabriela C. Carvalho and Jailson Alcaniz},
  journal= {arXiv preprint arXiv:2309.07263},
  year   = {2025}
}

Comments

10 pages, 24 figures