The connection between halo concentrations and assembly histories: a probe of gravity?

Oleśkiewicz, Piotr; Baugh, Carlton M; Ludlow, Aaron

doi:10.1093/mnras/stz2359

The connection between halo concentrations and assembly histories: a probe of gravity?

Oleśkiewicz, Piotr; Baugh, Carlton M; Ludlow, Aaron

Authors

Piotr Oleśkiewicz

Professor Carlton Baugh c.m.baugh@durham.ac.uk
Professor

Aaron Ludlow

Abstract

We use two high resolution N-body simulations, one assuming general relativity and the other the Hu-Sawicki form of f(R) gravity with |f¯R|=10−6⁠, to investigate the concentration–formation time relation of dark matter haloes. We assign haloes to logarithmically spaced mass bins, and fit median density profiles and extract median formation times in each bin. At fixed mass, haloes in modified gravity are more concentrated than those in GR, especially at low masses and at low redshift, and do not follow the concentration–formation time relation seen in GR. We assess the sensitivity of the relation to how concentration and formation time are defined, as well as to the segregation of the halo population by the amount of gravitational screening. We find a clear difference between halo concentrations and assembly histories displayed in modified gravity and those in GR. Existing models for the mass–concentration–redshift relation that have gained success in cold and warm dark matter models require revision in f(R) gravity.

Citation

Oleśkiewicz, P., Baugh, C. M., & Ludlow, A. (2019). The connection between halo concentrations and assembly histories: a probe of gravity?. Monthly Notices of the Royal Astronomical Society, 489(4), 4658-4668. https://doi.org/10.1093/mnras/stz2359

Journal Article Type	Article
Acceptance Date	Aug 21, 2019
Online Publication Date	Sep 7, 2019
Publication Date	Nov 30, 2019
Deposit Date	Sep 17, 2019
Publicly Available Date	Sep 17, 2019
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	489
Issue	4
Pages	4658-4668
DOI	https://doi.org/10.1093/mnras/stz2359

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Copyright Statement
This article has been accepted for publication in the Monthly notices of the Royal Astronomical Society ©: 2019 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.