English

Simple $\phi\Lambda$ CDM dynamics

General Relativity and Quantum Cosmology 2026-03-30 v2

Abstract

In this paper, we introduce the ϕΛ\phi\LambdaCDM model and compare it to the concordance model. We present their respective epoch evolutions, perform a detailed dynamical analysis for each model, and conduct a comparative analysis between the two. This study revitalizes these models by considering systems with a higher number of variables. Additionally, the ϕΛ\phi\LambdaCDM model we present is both more comprehensive and simpler than those found in the literature, as it accounts for all known epochs, including the radiation, matter, and dark energy phases. Notably, existing studies on this model often omit the radiation epoch and focus on simpler dynamics. We find that both models, the ϕΛ\phi\LambdaCDM and the Λ\LambdaCDM, can describe the generally accepted scenario of cosmic evolution, and current observations. Both models, describe qualitative and quantitative current observations about the epoch behaviour of the species of the universe. We find the ϕΛ\phi\LambdaCDM model has the following exotic transition from a \textit{dominant radiation energy density ratio} epoch, or a \textit{low scalar kinetic term energy density ratio} epoch, towards a \textit{dominant cosmological constant energy density ratio} epoch. This renders the ϕΛ\phi\LambdaCDM a richer phenomenologically model than the concordance cosmological model. The software of the study is publicly available online.

Cite

@article{arxiv.2502.03486,
  title  = {Simple $\phi\Lambda$ CDM dynamics},
  author = {Pierros Ntelis and Jackson Levi Said},
  journal= {arXiv preprint arXiv:2502.03486},
  year   = {2026}
}

Comments

16 pages, 4 figures, accepted for publication inInternational Journal of Geometric Methods in Modern Physics

R2 v1 2026-06-28T21:33:54.786Z