Exploring redshift-space distortions in large-scale structure
Exploring redshift-space distortions in large-scale structure
复制标题
DOI：
10.1088/1475-7516/2019/03/007
复制
发表时间：
2018-12
影响因子：
6.4
通讯作者：
Z. Vlah;M. White
中科院分区：
文献类型：
--
作者：
Z. Vlah;M. White
我们探索和比较了红移空间和实空间中大尺度结构观测的不同连接方式。这些包括拉格朗日空间的直接计算、矩展开和流模型的两种表述。我们首次推导了流模型的傅里叶空间版本，它产生了实空间和红移空间功率谱之间的代数关系，可以与早期的现象学模型进行比较。通过考虑组态和傅里叶空间中的红移空间2点函数，我们展示了如何将高斯流模型推广到高阶，这是一种系统的、计算上易于处理的方法。我们提出了红移空间中Zeldovich功率谱的一个封闭解，并以此作为一个框架来探索不同展开方法的收敛性。虽然我们使用Zeldovich近似来说明这些结果，但我们推导的许多形式主义和许多关系都超出了摄动理论，可以用于从n体模拟中测量的成分，或者用于其他需要分解笛卡尔张量乘以平面波的领域。最后，我们讨论了红移空间双谱、偏置和随机性以及拉格朗日微扰理论中高达1环阶的项。
We explore and compare different ways large-scale structure observables in redshift-space and real space can be connected. These include direct computation in Lagrangian space, moment expansions and two formulations of the streaming model. We derive for the first time a Fourier space version of the streaming model, which yields an algebraic relation between the real- and redshift-space power spectra which can be compared to earlier, phenomenological models. By considering the redshift-space 2-point function in both configuration and Fourier space, we show how to generalize the Gaussian streaming model to higher orders in a systematic and computationally tractable way. We present a closed-form solution to the Zeldovich power spectrum in redshift space and use this as a framework for exploring convergence properties of different expansion approaches. While we use the Zeldovich approximation to illustrate these results, much of the formalism and many of the relations we derive hold beyond perturbation theory, and could be used with ingredients measured from N-body simulations or in other areas requiring decomposition of Cartesian tensors times plane waves. We finish with a discussion of the redshift-space bispectrum, bias and stochasticity and terms in Lagrangian perturbation theory up to 1-loop order.