Modeling galaxy clustering on small scales to tighten constraints on dark energy and modified gravity
Yun Wang
备注：
9 pages, 3 figures. Test on mocks for 32-144Mpc/h added, along with additional discussions. MNRAS, in press. arXiv admin note: text overlap with arXiv:1404.5589
We present a new approach to measuring cosmic expansion history and growth rate of large scale structure using the anisotropic two dimensional galaxy correlation function (2DCF) measured from data; it makes use of the empirical modeling of small-scale galaxy clustering derived from numerical simulations by Zheng et al. (2013). We validate this method using mock catalogues, before applying it to the analysis of the CMASS sample from the Sloan Digital Sky Survey Data Release 10 (DR10) of the Baryon Oscillation Spectroscopic Survey (BOSS). We find that this method enables accurate and precise measurements of cosmic expansion history and growth rate of large scale structure. Modeling the 2DCF fully including nonlinear effects and redshift space distortions (RSD) in the scale range of 16 to 144 Mpc/h, we find H(0.57)r_s(z_d)/c=0.0459 +/- 0.0006, D_A(0.57)/r_s(z_d)=9.011 +/- 0.073, and f_g(0.57)σ_8(0.57)=0.476 +/- 0.050, which correspond to precisions of 1.3%, 0.8%, and 10.5% respectively. We have defined r_s(z_d) to be the sound horizon at the drag epoch computed using a simple integral, f_g(z) as the growth rate at redshift z, and σ_8(z) as the matter power spectrum normalization on 8Mpc/h scale at z. We find that neglecting the small-scale information significantly weakens the constraints on H(z) and D_A(z), and leads to a biased estimate of f_g(z). Our results indicate that we can significantly tighten constraints on dark energy and modified gravity by reliably modeling small-scale galaxy clustering.
Conventionally, in galaxy surveys, cosmological constraints on the growth and expansion history of the universe have been obtained from the measurements of redshift-space distortions and baryon acoustic oscillations embedded in the large-scale galaxy density field. In this paper, we study how well one can improve the cosmological constraints from the combination of the galaxy density field with velocity and tidal fields, which are observed via the kinetic Sunyaev-Zel'dovich (kSZ) and galaxy intrinsic alignment (IA) effects, respectively. For illustration, we consider the deep galaxy survey by …
Modified gravity and massive neutrino cosmologies are two of the most interesting scenarios that have been recently explored to account for possible observational deviations from the concordance $Λ$-cold dark matter ($Λ$CDM) model. In this context, we investigated the large-scale structure of the Universe by exploiting the \dustp simulations that implement, simultaneously, the effects of $f(R)$ gravity and massive neutrinos. To study the possibility of breaking the degeneracy between these two effects, we analysed the redshift-space distortions in the clustering of dark matter haloes at differ…
Marked statistics across the cosmic web: Environmental dependent clustering in modified gravity simulations
Kavli Institute for the Physics and Mathematics of the Universe (WPI)（宇宙物理与数学科学 Kavli 研究所）；The University of Tokyo Institutes for Advanced Study (UTIAS)（东京大学高等研究院）；Center for Data-Driven Discovery, Kavli IPMU (WPI), UTIAS, The University of Tokyo（东京大学数据驱动发现中心，Kavli IPMU (WPI)，UTIAS）；Department of Mathematical Physics, Institute of Physics, University of São Paulo（圣保罗大学物理学院数学物理系）；ILANCE, CNRS – University of Tokyo International Research Laboratory（CNRS-东京大学国际联合实验室 ILANCE）；Ecole Polytechnique（巴黎综合理工学院）
Improving the theoretical description of galaxy clustering on small scales is an important challenge in cosmology, as it can considerably increase the scientific return of forthcoming galaxy surveys -- e.g. tightening the bounds on neutrino masses and deviations from general relativity. In this paper, we propose and test a new model for the clustering of galaxies that is able to accurately describe redshift-space distortions even down to small scales. This model corresponds to a second-order perturbative Lagrangian bias expansion which is advected to Eulerian space employing a displacement fie…
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One of the seemingly strongest constraints on the fraction of dark matter in the form of primordial black holes (PBH) of ${\cal O}$(10)$\,M_\odot$ relies on the merger rate inferred from the binary BH merger events detected by LIGO/Virgo. The robustness of these bounds depends however on the accuracy with which the formation of PBH binaries in the early Universe can be described. We revisit the standard estimate of the merger rate, focusing on a couple of key ingredients: the spatial distribution of nearest neighbours and the initial clustering of PBHs associated to a given primordial power sp…
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The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measurements of the growth of structure and expansion rate at z=0.57 from anisotropic clustering
我们分析了斯隆数字巡天III重子振荡光谱巡天（BOSS）数据发布9（DR 9）样本中大质量星系的各向异性聚类，该样本由264，283个星系组成，红移范围为0.43 < z < 0.7，跨度为3，275平方度。这两个奇特的速度和错误的假设红移距离关系（“Alcock-Paczynski效应”）产生的聚类幅度和方向之间的相关性，相对于视线。我们对四极和四极关联函数的宽带形状的测量与尖锐的重子声学振荡（BAO）标准尺一起，同时约束了共动角直径距离（2190 +/- 61 Mpc）到z=0.57，哈勃膨胀率在z=0.57（92.4 +/- 4.5 km/s/Mpc），以及在相同红移下的结构增长率（d σ 8/d ln a = 0.43 +/- 0.069）。我们的分析提供了目前最好的直接测定DA和H的星系聚类数据使用这种技术。如果我们进一步假设LCDM扩展历史，我们的增长约束收紧到d σ 8/d ln a = 0.415 +/- 0.034。结合宇宙微波背景，我们对DA、H和生长的测量都分别需要z > 0.57的暗能量，当结合起来时意味着Ω_Λ = 0.74 +/- 0.016，与z<0.57的宇宙演化无关。在我们的配套论文（Samushia et al. prep）中，我们进一步探讨了这些观测的宇宙学意义。
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Using Global Gravitational Potential Weighted Correlation Function to Constrain Modified Gravity Models
State Key Laboratory of Dark Matter Physics, School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院暗物质物理全国重点实验室）；Key Laboratory for Particle Astrophysics and Cosmology (MOE) / Shanghai Key Laboratory for Particle Physics and Cosmology（粒子天体物理与宇宙学教育部重点实验室/上海粒子物理与宇宙学重点实验室）；Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交通大学李政道研究所）
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Photometric galaxy surveys constitute a powerful cosmological probe but rely on the accurate characterization of their redshift distributions using only broadband imaging, and can be very sensitive to incomplete or biased priors used for redshift calibration. Sánchez & Bernstein (2019) presented a hierarchical Bayesian model which estimates those from the robust combination of prior information, photometry of single galaxies and the information contained in the galaxy clustering against a well-characterized tracer population. In this work, we extend the method so that it can be applied to real…
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