English

$\Lambda CDM$ periodic cosmology

General Relativity and Quantum Cosmology 2020-04-17 v1

Abstract

We examine the possibility that Universe expansion be made of some ΛCDM\Lambda CDM expansions repeating periodically, separated by some inflation and radiation dominated phases. This so-called ΛCDM\Lambda CDM periodic cosmology is motivated by the possibility that inflation and the present phase of accelerated expansion be due to the same dark energy. Then, in a phase space showing the variation of matter density parameter Ωm\Omega_m with respect to this of the radiation Ωr\Omega_r, the curve Ωm(Ωr)\Omega_m(\Omega_r) looks like a closed trajectory that Universe could run through forever. In this case, the end of the expansion acceleration of the ΛCDM\Lambda CDM phase is the beginning of a new inflation phase. We show that such a scenario implies the coupling of matter and/or radiation to dark energy. We consider the simplest of these ΛCDM\Lambda CDM periodic models i.e. a vacuum energy coupled to radiation. From matter domination phase to today, it behaves like a ΛCDM\Lambda CDM model, then followed by an inflation phase. But a sudden and fast decay of the dark energy into radiation periodically ends the expansion acceleration. This leads to a radiation dominated Universe preceding a new ΛCDM\Lambda CDM type expansion. The model is constrained with Markov Chain Monte Carlo simulations using supernovae, Hubble expansion, BAO and CMB data and fits the data as well as the ΛCDM\Lambda CDM one.

Keywords

Cite

@article{arxiv.2004.07552,
  title  = {$\Lambda CDM$ periodic cosmology},
  author = {Stephane Fay},
  journal= {arXiv preprint arXiv:2004.07552},
  year   = {2020}
}

Comments

9 pages, 7 figures, accepted for publication in MNRAS

R2 v1 2026-06-23T14:53:29.529Z