English

Spherical collapse model in agegraphic dark energy cosmologies

General Relativity and Quantum Cosmology 2017-10-11 v2 Cosmology and Nongalactic Astrophysics

Abstract

Under the commonly used spherical collapse model, we study how dark energy affects the growth of large scale structures of the Universe in the context of agegraphic dark energy models. The dynamics of the spherical collapse of dark matter halos in nonlinear regimes is determined by the properties of the dark energy model. We show that the main parameters of the spherical collapse model are directly affected by the evolution of dark energy in the agegraphic dark energy models. We compute the spherical collapse quantities for different values of agegraphic model parameter α\alpha in two different scenarios: first, when dark energy does not exhibit fluctuations on cluster scales, and second, when dark energy inside the overdense region collapses similar to dark matter. Using the Sheth-Tormen and Reed mass functions, we investigate the abundance of dark matter halos in the framework of agegraphic dark energy cosmologies. The model parameter α\alpha is a crucial parameter in order to count the abundance of dark matter halos. Specifically, the present analysis suggests that the agegraphic dark energy model with bigger (smaller) value of α\alpha predicts less (more) virialized halos with respect to that of Λ\LambdaCDM cosmology. We also show that in agegraphic dark energy models, the number of halos strongly depends on clustered or uniformed distributions of dark energy.

Keywords

Cite

@article{arxiv.1708.08915,
  title  = {Spherical collapse model in agegraphic dark energy cosmologies},
  author = {M. Rezaei and M. Malekjani},
  journal= {arXiv preprint arXiv:1708.08915},
  year   = {2017}
}

Comments

14 pages, 7 figures. Accepted in Physical Review D