Interpreting large-scale redshift-space distortion measurements
Interpreting large-scale redshift-space distortion measurements
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DOI：
10.1111/j.1365-2966.2011.20169.x
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发表时间：
2011-02
影响因子：
4.8
通讯作者：
L. Samushia;W. Percival;A. Raccanelli
中科院分区：
文献类型：
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作者：
L. Samushia;W. Percival;A. Raccanelli
描述大尺度红移空间扭曲（RSD）的最简单理论，基于线性理论和遥远星系，依赖于宇宙结构的增长，这表明可以从星系巡天构建强有力的广义相对论检验。随着数据集变得越来越大，预期的约束条件越来越精确，需要评估RSD遵循简单理论的程度，以便我们不会通过引入不准确的简化假设将系统误差引入到测试中。我们研究的影响，样品的几何形状，非线性过程和偏差引起的我们缺乏了解的径向星系分布RSD测量。使用斯隆数字巡天II（SDSS-II）亮红星系数据的大型暗物质模拟套件（Large Suite of Dark Matter Simulations），这些效应在20%的水平上被证明是重要的。包括它们，我们可以在30-200 h−1 Mpc的尺度上精确地模拟这些模拟目录中恢复的聚类。应用这一分析，从SDSS-II数据中稳健地测量描述宇宙生长历史的参数，给出了f（z= 0.25）σ8（z= 0.25）= 0.3512 ± 0.0583，（z= 0.37）σ8（z= 0.37）= 0.4602 ± 0.0378，当没有对生长速率施加先验时，背景几何假定遵循Λ冷暗物质（ΛCDM）模型，并具有威尔金森微波各向异性探测器（WMAP）+Ia型超新星先验。标准WMAP约束的ΛCDM模型在广义相对论下的预测值为f（z= 0.25）σ8（z= 0.25）= 0.4260 ± 0.0141和f（z= 0.37）σ8（z= 0.37）= 0.4367 ± 0.0136，与这些测量值完全一致。
The simplest theory describing large-scale redshift-space distortions (RSD), based on linear theory and distant galaxies, depends on the growth of cosmological structure, suggesting that strong tests of general relativity can be constructed from galaxy surveys. As data sets become larger and the expected constraints more precise, the extent to which the RSD follow the simple theory needs to be assessed in order that we do not introduce systematic errors into the tests by introducing inaccurate simplifying assumptions. We study the impact of the sample geometry, non-linear processes and biases induced by our lack of understanding of the radial galaxy distribution on RSD measurements. Using Large Suite of Dark Matter Simulations of the Sloan Digital Sky Survey II (SDSS-II) luminous red galaxy data, these effects are shown to be important at the level of 20 per cent. Including them, we can accurately model the recovered clustering in these mock catalogues on scales 30–200 h−1 Mpc. Applying this analysis to robustly measure parameters describing the growth history of the Universe from the SDSS-II data gives f(z= 0.25)σ8(z= 0.25) = 0.3512 ± 0.0583 and f(z= 0.37)σ8(z= 0.37) = 0.4602 ± 0.0378 when no prior is imposed on the growth rate, and the background geometry is assumed to follow a Λ cold dark matter (ΛCDM) model with the Wilkinson Microwave Anisotropy Probe (WMAP)+Type Ia supernova priors. The standard WMAP constrained ΛCDM model with general relativity predicts f(z= 0.25)σ8(z= 0.25) = 0.4260 ± 0.0141 and f(z= 0.37)σ8(z= 0.37) = 0.4367 ± 0.0136, which is fully consistent with these measurements.