Peak exclusion, stochasticity and convergence of perturbative bias expansions in 1+1 gravity
Peak exclusion, stochasticity and convergence of perturbative bias expansions in 1+1 gravity
复制标题
1 1 引力中微扰偏差展开的峰值排除、随机性和收敛性
DOI：
10.1093/mnras/stv2973
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发表时间：
2015
影响因子：
4.8
通讯作者：
C. Pichon
中科院分区：
文献类型：
--
作者：
T. Baldauf;S. Codis;V. Desjacques;C. Pichon
代表暗物质的一维宇宙学随机场的拉格朗日峰被用作有偏示踪剂目录的代理，以调查在两晕项的小尺度排斥。两点相关函数的峰值的一个给定的高度的数值估计和解析近似，是有效的禁区内推导。这些示踪剂的功率谱进行了研究，并显示出明显的偏离泊松噪声在低频率。在大尺度下，讨论了扰动偏置展开的收敛性。最后，我们超越了高斯统计的初始条件，并调查了随后的演变的两点集群的峰值通过其Zel'dovich弹道位移，澄清排斥效应如何混合与非线性引力演化引起的尺度依赖性。虽然恢复了预期的大规模分离极限，但在禁区内发现了重大偏差，特别是在以后的时间内倾向于减少。即使这些发现适用于一维示踪剂的聚类，他们提供了有用的见解晕排斥和它的影响的两个晕术语。
The Lagrangian peaks of a 1D cosmological random field representing dark matter are used as a proxy for a catalogue of biased tracers in order to investigate the small-scale exclusion in the two-halo term. The two-point correlation function of peaks of a given height is numerically estimated and analytical approximations that are valid inside the exclusion zone are derived. The resulting power spectrum of these tracers is investigated and shows clear deviations from Poisson noise at low frequencies. On large scales, the convergence of a perturbative bias expansion is discussed. Finally, we go beyond Gaussian statistics for the initial conditions and investigate the subsequent evolution of the two-point clustering of peaks through their Zel'dovich ballistic displacement, to clarify how exclusion effects mix up with scale-dependencies induced by nonlinear gravitational evolution. While the expected large-scale separation limit is recovered, significant deviations are found in the exclusion zone that tends in particular to be reduced at later times. Even though these findings apply to the clustering of one-dimensional tracers, they provide useful insights into halo exclusion and its impact on the two-halo term.