English

Redshift ~2.7 is not special

Astrophysics of Galaxies 2025-09-24 v2

Abstract

Galikyan et al. (2025) reported a statistically significant change in galaxy spectral properties at redshift zz \simeq 2.7 based on a Kolmogorov Stochasticity Parameter analysis of JWST spectroscopic data of galaxies. In this comment, we demonstrate that their result is critically driven by a single outlier in the dataset. This outlier arises from the use of a questionable redshift estimate for one spectrum. When the outlier is removed or the redshift is corrected, the claimed transition at zz \simeq 2.7 disappears entirely. By independently reproducing their analysis, we demonstrate that the claimed feature is not a robust statistical signal, but an artefact of this anomalous data point.

Cite

@article{arxiv.2506.07774,
  title  = {Redshift ~2.7 is not special},
  author = {Prajwel Joseph},
  journal= {arXiv preprint arXiv:2506.07774},
  year   = {2025}
}

Comments

Accepted for publication in A&A

R2 v1 2026-07-01T03:07:03.203Z