Cosmological parameters from the BOSS galaxy power spectrum
Cosmological parameters from the BOSS galaxy power spectrum
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DOI：
10.1088/1475-7516/2020/05/042
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发表时间：
2019-09
影响因子：
6.4
通讯作者：
M. Ivanov;M. Simonovi'c;M. Zaldarriaga
中科院分区：
文献类型：
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作者：
M. Ivanov;M. Simonovi'c;M. Zaldarriaga
我们提出了从公开可用的重子振荡光谱调查（BOSS）数据中对傅里叶空间各向异性星系群集的宇宙学参数测量。与以往的研究相比，我们的分析有两个主要的新特点。首先，我们使用了一个完整的微扰理论模型，该模型适当地考虑了暗物质聚类、短尺度物理、星系偏差、红移空间畸变和大尺度体流的非线性效应。其次，我们采用马尔可夫链蒙特卡罗技术，并在扫描不同宇宙学时不断重新评估全功率谱可能性。我们的基线分析假设最小值ΛCDM，在一个合理的窄范围内改变中微子质量，固定原始功率谱倾斜，并在物理重子密度ωb之前使用大爆炸核合成。在此模型中，我们得到了哈勃常数H0=(67.9±1.1)km s−1Mpc−1，物质密度分数Ωm=0.295±0.010，质量波动幅度σ8=0.721±0.043。这些参数是直接从BOSS数据中测量出来的，独立于普朗克宇宙微波背景观测。扫描功率谱倾斜或放松其他先验不会显著改变我们的主要结论。最后，我们讨论了BOSS功率谱的信息含量，并表明它是由重子声学振荡的位置和功率谱形状主导的。我们认为，阿尔科克-帕钦斯基效应的贡献是边际的ΛCDM，但变得重要的非极小宇宙学模型。
We present cosmological parameter measurements from the publicly available Baryon Oscillation Spectroscopic Survey (BOSS) data on anisotropic galaxy clustering in Fourier space. Compared to previous studies, our analysis has two main novel features. First, we use a complete perturbation theory model that properly takes into account the non-linear effects of dark matter clustering, short-scale physics, galaxy bias, redshift-space distortions, and large-scale bulk flows. Second, we employ a Markov-Chain Monte-Carlo technique and consistently reevaluate the full power spectrum likelihood as we scan over different cosmologies. Our baseline analysis assumes minimal ΛCDM, varies the neutrino masses within a reasonably tight range, fixes the primordial power spectrum tilt, and uses the big bang nucleosynthesis prior on the physical baryon density ωb. In this setup, we find the following late-Universe parameters: Hubble constant H0=(67.9± 1.1) km s−1Mpc−1, matter density fraction Ωm=0.295± 0.010, and the mass fluctuation amplitude σ8=0.721± 0.043. These parameters were measured directly from the BOSS data and independently of the Planck cosmic microwave background observations. Scanning over the power spectrum tilt or relaxing the other priors do not significantly alter our main conclusions. Finally, we discuss the information content of the BOSS power spectrum and show that it is dominated by the location of the baryon acoustic oscillations and the power spectrum shape. We argue that the contribution of the Alcock-Paczynski effect is marginal in ΛCDM, but becomes important for non-minimal cosmological models.