On the primordial information available to galaxy redshift surveys
On the primordial information available to galaxy redshift surveys
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DOI：
10.1088/1475-7516/2021/06/024
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发表时间：
2020-08
影响因子：
6.4
通讯作者：
M. McQuinn
中科院分区：
文献类型：
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作者：
M. McQuinn
我们调查的原始信息，可以重建光谱星系调查，以及什么设置在低波数重建的噪音，通过研究一个简化的宇宙中，星系的Zeldovich位移拉格朗日峰的线性密度场。对于本研究中的一些，我们进一步采取直观的线性化限制，其中重建是一个凸问题，但其中的解决方案也是一个完整的非线性问题的解决方案，限制重建的有效性。线性化重建的结果类似的互相关系数与线性输入字段作为我们的完全非线性算法。线性重建也产生类似的互相关系数的宇宙学N体模拟，这表明，现有的重建算法提取的大部分可访问的信息的重建尝试。我们的方法有助于解释为什么重建算法准确地再现初始条件的一些特征波数，在这一点上有一个快速过渡到几乎没有相关性。这种转变是由重建的约束条件（调查中的星系数量）的数量，而不是由散粒噪声超过聚类信号，传统上认为。我们进一步表明，在线性尺度上的模式可以重建精度远低于散粒噪声的期望，如果星系拉格朗日位移可以充分约束。我们提供了理想化的例子，非线性重建散粒噪声可以优于。
We investigate the amount of primordial information that can be reconstructed from spectroscopic galaxy surveys, as well as what sets the noise in reconstruction at low wavenumbers, by studying a simplified universe in which galaxies are the Zeldovich displaced Lagrangian peaks in the linear density field. For some of this study, we further take an intuitive linearized limit in which reconstruction is a convex problem but where the solution is also a solution to the full nonlinear problem, a limit that bounds the effectiveness of reconstruction. The linearized reconstruction results in similar cross correlation coefficients with the linear input field as our full nonlinear algorithm. The linearized reconstruction also produces similar cross correlation coefficients to those of reconstruction attempts on cosmological N-body simulations, which suggests that existing reconstruction algorithms are extracting most of the accessible information. Our approach helps explain why reconstruction algorithms accurately reproduce the initial conditions up to some characteristic wavenumber, at which point there is a quick transition to almost no correlation. This transition is set by the number of constraints on reconstruction (the number of galaxies in the survey) and not by where shot noise surpasses the clustering signal, as is traditionally thought. We further show that on linear scales a mode can be reconstructed with precision well below the shot noise expectation if the galaxy Lagrangian displacements can be sufficiently constrained. We provide idealized examples of nonlinear reconstruction where shot noise can be outperformed.