We compare the predicted conditional mass function (CMF) of dark matter halos from two theoretical prescriptions against numerical N-body simulations, both in overdense and underdense regions and at different Eulerian scales ranging from $5$ to $30\,h^{-1}\,$Mpc. In particular, we consider in detail a locally-implemented rescaling of the unconditional mass function (UMF) already discussed in the literature, and also a generalization of the standard rescaling method described in the extended Press-Schechter formalism. First, we test the consistency of these two rescalings by verifying the normalization of the CMF at different scales, and showing that none of the proposed cases provides a normalized CMF. In order to satisfy the normalization condition, we include a modification in the rescaling procedure. After this modification, the resulting CMF generally provides a better description of numerical results. We finally present an analytical fit to the ratio between the CMF and the UMF (also known as the matter-to-halo bias function) in underdense regions, which could be of special interest to speed-up the computation of the halo abundance when studying void statistics. In this case, the CMF prescription based on the locally-implemented rescaling provides a slightly better description of the numerical results when compared to the standard rescaling.
Halo statistics in non-Gaussian cosmologies: the collapsed fraction, conditional mass function, and halo bias from the path-integral excursion set method
A Halo Model of Local IRAS Galaxies Selected at 60 Micron Using Conditional Luminosity Functions
Using conditional luminosity functions (CLFs) which encode the luminosity distribution of galaxies as a function of halo mass, we construct a halo model of IRAS galaxies selected at 60 micron. An abundance matching technique is used to link galaxy luminosity to the host halo mass. The shape of the mass - light relation at 60 micron is different from those derived at r-, K- and B-band. This is because the 60 micron LF can not be fitted by a Schechter function with a sharp exponential cutoff. We then seek the parameters in the CLFs that best fit the LF and power spectrum. We find that the predic…
Testing standard perturbation theory and the Eulerian local biasing scheme against N-body simulations
我们测试三阶标准微扰理论（SPT）作为一个近似的非线性宇宙结构的形成。本文从两个高分辨率宇宙学模拟的初始条件出发，采用一种新的方法，用标准粒子群方法数值计算三维暗物质密度场。计算出的密度场进行比较的非线性暗物质场的模拟都逐点和统计。对于平滑尺度超过8兆秒差距/小时，它显示了良好的协议，红移0。我们提出了一个简单的拟合公式来关联线性和非线性密度对比度，该公式在百分比水平上精确地恢复了0 <= z <= 10的非线性时间演化。为了解决模拟中确定的物质场和晕之间的偏置问题，我们采用欧拉局部偏置模型（ELB），包括三阶非线性偏置。偏置参数通过拟合晕和物质密度的散点图（均来自模拟和SPT）获得。利用这些偏置参数，我们可以重建晕密度场。我们发现，这种重建是不能够捕捉所有的细节晕分布。我们研究如何以及大尺度偏差可以描述为一个常数，如果它对应于线性偏置参数b_1的局部偏置模型。我们还讨论了如何以及从重建的晕密度场的晕-晕功率谱和晕-质量互谱同意从模拟相应的统计。结果表明，虽然SPT是一个很好的近似的物质场的适当大的平滑尺度，即使在红移0，ELB模型只能解释晕密度场的一些属性。
Testing the isothermal Jeans model for self-interacting dark matter halos in the collapse phase
School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Donostia International Physics Center (DIPC)（圣塞巴斯蒂安国际物理中心）；Department of Astronomy, Peking University（北京大学天文学系）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；Department of Physics and Astronomy, University of California, Riverside（加州大学河滨分校物理与天文学系）
Towards Accurate Modelling of Galaxy Clustering on Small Scales: Testing the Standard $Λ\mathrm{CDM}$ + Halo Model
用晕模型解释星系的小尺度成团现象可以阐明星系与暗物质晕之间的联系。不幸的是，建模通常不够准确，无法在统计上排除模型。因此，很难使用小尺度编码的信息来测试宇宙学模型或探测星系-晕连接的微妙特征。在本文中，我们试图推动晕模型的"准确"的制度，完全数值模拟为基础的方法和统计和系统误差的仔细治疗。通过我们的前向建模方法，我们可以将聚类统计纳入传统的两点统计之外。我们使用这种建模方法来测试标准的$Λ\mathrm{CDM}$+晕模型对SDSS DR 7星系的聚类。具体地说，我们使用投影关联函数，群多重性函数和星系数密度作为约束条件。我们发现，虽然模型分别拟合每个统计量，但它很难同时拟合它们。添加组统计量会导致对模型进行更严格的测试，并对模型参数进行更严格的约束。我们探讨了不同的晕定义和宇宙学模型的影响，发现改变宇宙学有显着的差异。我们尝试的最成功的模型（普朗克宇宙学与Mvir晕）匹配的低光度星系的集群，但表现出2.3 $σ$张力与发光星系的集群，从而提供了证据，"标准"晕模型需要扩展。这项工作打开了大门，增加有趣的自由光环模型，并包括额外的聚类统计作为约束。
Testing subhalo abundance matching with galaxy kinematics
University of Oxford（牛津大学）；University of Cambridge（剑桥大学）；University of Manchester（曼彻斯特大学）；University of Portsmouth（朴茨茅斯大学）；University of the Western Cape（西开普大学）
