Using Voids to Unscreen Modified Gravity

Falck, Bridget; Koyama, Kazuya; Zhao, Gong-Bo; Cautun, Marius

doi:10.1093/mnras/stx3288

Using Voids to Unscreen Modified Gravity

Falck, Bridget; Koyama, Kazuya; Zhao, Gong-Bo; Cautun, Marius

Authors

Bridget Falck

Kazuya Koyama

Gong-Bo Zhao

Marius Cautun

Abstract

The Vainshtein mechanism, present in many models of gravity, is very effective at screening dark matter halos such that the fifth force is negligible and general relativity is recovered within their Vainshtein radii. Vainshtein screening is independent of halo mass and environment, in contrast to e.g. chameleon screening, making it difficult to test. However, our previous studies have found that the dark matter particles in filaments, walls, and voids are not screened by the Vainshtein mechanism. We therefore investigate whether cosmic voids, identified as local density minima using a watershed technique, can be used to test models of gravity that exhibit Vainshtein screening. We measure density, velocity, and screening profiles of stacked voids in cosmological N-body simulations using both dark matter particles and dark matter halos as tracers of the density field. We find that the voids are completely unscreened, and the tangential velocity and velocity dispersion profiles of stacked voids show a clear deviation from ΛCDM at all radii. Voids have the potential to provide a powerful test of gravity on cosmological scales.

Citation

Falck, B., Koyama, K., Zhao, G., & Cautun, M. (2018). Using Voids to Unscreen Modified Gravity. Monthly Notices of the Royal Astronomical Society, 475(3), 3262-3272. https://doi.org/10.1093/mnras/stx3288

Journal Article Type	Article
Acceptance Date	Dec 15, 2017
Online Publication Date	Dec 22, 2017
Publication Date	Apr 11, 2018
Deposit Date	Jan 2, 2018
Publicly Available Date	Jan 3, 2018
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	475
Issue	3
Pages	3262-3272
DOI	https://doi.org/10.1093/mnras/stx3288

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This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2017. The Authors.
Published by Oxford University Press on behalf of the Royal Astronomical Society.