English

The cosmic timeline implied by the highest redshift quasars

Cosmology and Nongalactic Astrophysics 2024-12-05 v1 Astrophysics of Galaxies

Abstract

The conventional picture of supermassive black-hole growth in the standard model had already been seriously challenged by the emergence of 109  M\sim 10^9\;M_\odot quasars at z7.5z\sim 7.5, conflicting with the predicted formation of structure in the early Λ\LambdaCDM Universe. But the most recent {\it JWST} discovery of a 108  M\sim 10^8\;M_\odot source at z10.1z\sim 10.1 argues even more strongly against the possibility that these black holes were created in Pop II or III supernovae, followed by Eddington-limited accretion. Attempts at resolving this anomaly have largely focused on the formation of seeds via an exotic, direct collapse of primordial gas to an initial mass 105  M\sim 10^5\;M_\odot -- a process that has never been seen anywhere in the cosmos. Our goal in this {\it Letter} is to demonstrate that the emergence of these black holes is instead fully consistent with standard astrophysics in the context of the alternative Friedmann-Lema\^itre-Robertson-Walker cosmology known as the Rh=ctR_{\rm h}=ct universe. We show that, while the predicted evolution in the standard model is overly compressed, the creation, growth and appearance of such high-zz quasars fall comfortably within the evolutionary history in this cosmology, thereby adding considerable observational support to the existing body of evidence favoring it over the standard scenario.

Keywords

Cite

@article{arxiv.2412.02706,
  title  = {The cosmic timeline implied by the highest redshift quasars},
  author = {Fulvio Melia},
  journal= {arXiv preprint arXiv:2412.02706},
  year   = {2024}
}

Comments

6 pages, 2 figures. Accepted for publication in EPJ-C Letters

R2 v1 2026-06-28T20:21:50.815Z