English

Can the Universe decelerate in the future?

Cosmology and Nongalactic Astrophysics 2024-01-29 v2

Abstract

The possibility of an expanding decelerating Universe in the distant future is investigated in the context of a quintessence scalar field cosmology. Such a conceivable evolution is tested against SNe Ia and H(z)H(z) cosmic chronometers data, and also through a model independent method based on Gaussian Processes. The scalar field model is an extension of the exponential Ratra-Peebles (RP) quintessential cosmology whose potential now depends on a pair of parameters (α,λ)\alpha, \lambda) and predicts a decelerated expansion in the future. Different from RP approach the α\alpha parameter allows for a decelerating cosmology in the future thereby frustrating the inevitable evolution for a de Sitter Cosmology as predicted by the cosmic concordance model (Λ\LambdaCDM). The statistical model analysis is updated with the most recent SNe Ia and H(z)H(z) data thereby obtaining H0=68.6±3.7H_0 = 68.6\pm3.7 km/s/Mpc, ΩΦ0=0.7350.069+0.083\Omega_{\Phi0} = 0.735^{+0.083}_{-0.069} , α<6.56\alpha < 6.56 and λ<0.879\lambda< 0.879 (at 2σ2\sigma c.l.). It is also found that the extended RP model allows for a future deceleration both for H(z)H(z) and SNe Ia data. In the (model-independent) Gaussian Processes analysis, however, future deceleration is allowed only in the case of H(z)H(z) data.

Keywords

Cite

@article{arxiv.2302.01946,
  title  = {Can the Universe decelerate in the future?},
  author = {A. A. Escobal and J. F. Jesus and S. H. Pereira and J. A. S. Lima},
  journal= {arXiv preprint arXiv:2302.01946},
  year   = {2024}
}

Comments

10 pages, 5 figures. Accepted for publication in Physical Review D

R2 v1 2026-06-28T08:31:39.864Z