文章基本信息

标题：N-body simulations of γ gravity
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作者：Marcelo Vargas dos Santos ; Marcelo Vargas dos Santos ; Hans A. Winther 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2016
卷号：587
页码：1-10
DOI：10.1051/0004-6361/201527645
语种：English
出版社：EDP Sciences
摘要：We have investigated structure formation in the γ gravity f(R) model with N-body simulations. The γ gravity model is a proposal which, unlike other viable f(R) models, not only changes the gravitational dynamics, but can in principle also have signatures at the background level that are different from those obtained in ΛCDM (Cosmological constant, Cold Dark Matter). The aim of this paper is to study the nonlinear regime of the model in the case where, at late times, the background differs from ΛCDM. We quantify the signatures produced on the power spectrum, the halo mass function, and the density and velocity profiles. To appreciate the features of the model, we have compared it to ΛCDM and the Hu-Sawicki f(R) models. For the considered set of parameters we find that the screening mechanism is ineffective, which gives rise to deviations in the halo mass function that disagree with observations. This does not rule out the model per se, but requires choices of parameters such that | fR0 | is much smaller, which would imply that its cosmic expansion history cannot be distinguished from ΛCDM at the background level.
关键词：gravitation;dark energy;galaxies: clusters: general;large-scale structure of Universe;galaxies: halos