English

Can a void mimic the $\Lambda$ in $\Lambda$CDM?

Cosmology and Nongalactic Astrophysics 2015-12-17 v2 General Relativity and Quantum Cosmology

Abstract

We investigate Lema\^itre-Tolman-Bondi (LTB) models, whose early time evolution and bang time are homogeneous and the distance - redshift relation and local Hubble parameter are inherited from the Λ\LambdaCDM model. We show that the obtained LTB models and the Λ\LambdaCDM model predict different relative local expansion rates and that the Hubble functions of the models diverge increasingly with redshift. The LTB models show tension between low redshift baryon acoustic oscillation and supernova observations and including Lyman-α\alpha forest or cosmic microwave background observations only accentuates the better fit of the Λ\LambdaCDM model compared to the LTB model. The result indicates that additional degrees of freedom are needed to explain the observations, for example by renouncing spherical symmetry, homogeneous bang time, negligible effects of pressure, or the early time homogeneity assumption.

Keywords

Cite

@article{arxiv.1503.08045,
  title  = {Can a void mimic the $\Lambda$ in $\Lambda$CDM?},
  author = {Peter Sundell and Edvard Mörtsell and Iiro Vilja},
  journal= {arXiv preprint arXiv:1503.08045},
  year   = {2015}
}

Comments

27 pages, 11 figures

R2 v1 2026-06-22T09:03:41.412Z