Challenges in constraining gravity with cosmic voids
Challenges in constraining gravity with cosmic voids
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DOI：
10.1103/physrevd.107.124008
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发表时间：
2022-12
影响因子：
5
通讯作者：
C. Wilson;R. Bean
中科院分区：
文献类型：
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作者：
C. Wilson;R. Bean
我们比较了nDGP和$f（R）$重力模型和GR使用N体模拟的空隙大小和聚类统计。我们展示了如何考虑来自模拟星系目录的统计数据，而不仅仅是暗物质晕。GR和$f（R）$模型的空隙大小函数之间的显着差异，目前当使用暗物质晕确定空隙时，空隙被删除时，更现实地，从模拟星系示踪剂的晕。空径向速度和速度分散在$f（R）$和nDGP模型增强相对于GR在晕和模拟星系识别的空隙。尽管如此，我们发现来自模拟星系示踪剂的红移空间空四极矩在三个引力模型中惊人地相似。高斯流模型（GSM）被证明是准确地重建$\xi_2$在修改后的重力模型，我们采用GSM，使用功能导数的方法，分析的不敏感性$\xi_2$的重力模型。假设线性理论，我们证明了空四极矩是修正引力理论中红移空间增长率参数$\beta=f/B$的无偏估计.
We compare void size and clustering statistics for nDGP and $f(R)$ gravity models and GR using N-body simulations. We show how it is critical to consider the statistics derived from mock galaxy catalogs rather than the dark matter halos alone. Marked differences between the void size functions for GR and $f(R)$ models which present when voids are identified using dark matter halos are removed when voids are identified, more realistically, from mock galaxy tracers of the halos. The void radial velocities and velocity dispersions in the $f(R)$ and nDGP models are enhanced relative to GR in both halos and mock galaxy identified voids. Despite this, we find that the redshift space void quadrupole moments derived from the mock galaxy tracers are strikingly similar across the three gravity models. The Gaussian Streaming Model (GSM) is shown to accurately reconstruct $\xi_2$ in modified gravity models and we employ the GSM, using a functional derivative approach, to analyze the insensitivity of $\xi_2$ to the gravity model. Assuming linear theory, we show the void quadrupole to be an unbiased estimator of the redshift space growth rate parameter $\beta=f/b$ in the modified gravity theories.