English

Testing time-delayed cosmology

Cosmology and Nongalactic Astrophysics 2023-01-04 v2 General Relativity and Quantum Cosmology

Abstract

Motivated by the proposed time-delayed cosmology in the primordial inflationary era, we consider the application of the delayed Friedmann equation in the late-time Universe and explore some of its observable consequences. We study the background evolution predicted by the delayed Friedmann equation and determine the growth of Newtonian perturbations in this delayed background. We reveal smoking-gun imprints of time-delayed cosmology that can be traced to derivative discontinuities generic in delay differential equations. We show that a late-time cosmic delay is statistically consistent with Hubble expansion rate and growth data. Based on these observables, we compute a nonzero best estimate for the time delay parameter and find that the Bayesian evidence does not strongly rule out a late-time time delay but warrants the subject further study.

Keywords

Cite

@article{arxiv.2111.10742,
  title  = {Testing time-delayed cosmology},
  author = {C. J. Palpal-latoc and Reginald Christian Bernardo and Ian Vega},
  journal= {arXiv preprint arXiv:2111.10742},
  year   = {2023}
}

Comments

25 pages, 17 figures, added references, extended discussion, comments welcome

R2 v1 2026-06-24T07:46:11.502Z