English

Density profiles and voids in modified gravity models

Cosmology and Nongalactic Astrophysics 2009-11-11 v1

Abstract

We study the formation of voids in a modified gravity model in which gravity is generically stronger or weaker on large scales. We show that void abundances provide complementary information to halo abundances: if normalized to the CMB, models with weaker large-scale gravity have smaller large scale power, fewer massive halos and fewer large voids, although the scalings are not completely degenerate with σ8\sigma_8. Our results suggest that, in addition to their abundances, halo and void density profiles may also provide interesting constraints on such models: stronger large scale gravity produces more concentrated halos, and thinner void walls. This potentially affects the scaling relations commonly assumed to translate cluster observables to halo masses, potentially making these too, useful probes of gravity.

Keywords

Cite

@article{arxiv.0911.1829,
  title  = {Density profiles and voids in modified gravity models},
  author = {Matthew C. Martino and Ravi K. Sheth},
  journal= {arXiv preprint arXiv:0911.1829},
  year   = {2009}
}

Comments

11 pages, 10 figures

R2 v1 2026-06-21T14:09:34.021Z