N-body Simulations of $\gamma$ Gravity
N-body Simulations of $\gamma$ Gravity
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DOI：
10.1051/0004-6361/201527645
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发表时间：
2016-01
期刊：
影响因子：
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通讯作者：
M. V. Santos;H. Winther;D. Mota;I. Waga
中科院分区：
文献类型：
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作者：
M. V. Santos;H. Winther;D. Mota;I. Waga
我们研究了$\gamma$重力$f（R）$模型的{\itN}体模拟中的结构形成。与其他可行的$f（R）$模型不同，$\gamma$引力模型不仅改变了引力动力学，而且原则上也可以在背景水平上具有不同于$\Lambda$CDM（宇宙常数，冷暗物质）的签名。本文的目的是研究的情况下，在晚些时候，背景不同于$\Lambda$CDM的模型的非线性政权。我们量化的签名产生的功率谱，晕质量函数，密度和速度分布。为了了解该模型的功能，我们将其与$\Lambda$CDM和Hu-Sawicki $f（R）$模型进行了比较。对于所考虑的一组参数，我们发现，筛选机制是无效的，这会引起偏差的晕质量函数，不同意的意见。这并不排除模型本身，但需要选择参数，|f_{R0}|$要小得多，这意味着它的宇宙膨胀历史在背景水平上无法与$\Lambda$CDM区分开来。
We have investigated structure formation in the $\gamma$ gravity $f(R)$ model with {\it N}-body simulations. The $\gamma$ 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 $\Lambda$CDM (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 $\Lambda$CDM. 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 $\Lambda$CDM 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 $|f_{R0}|$ is much smaller, which would imply that its cosmic expansion history cannot be distinguished from $\Lambda$CDM at the background level.