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arXiv 1805.08752astro-ph.CO
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三维Minkowski张量--由红移空间畸变产生的各向异性的探讨

Minkowski Tensors in Three Dimensions - Probing the Anisotropy Generated by Redshift Space Distortion

Stephen Appleby, Pravabati Chingangbam, Changbom Park, K. P. Yogendran, P. K. Joby

摘要:

本文将Minkowski张量统计量应用于三维高斯随机场。闵可夫斯基张量包含关于偏移集的方向和形状的信息,这在标量闵可夫斯基泛函中不存在。它们可用于量化全局首选方向,并提供关于场子集的平均形状的信息。这使得它们成为测量低红移物质密度场中由红移空间畸变产生的各向异性信号的理想统计量。我们回顾了三维Minkowski张量统计量的定义,重点是两个坐标不变量$W^{0,2}_{1}$和$W^{0,2}_{2}$。我们计算了各向同性高斯随机场的这些$3 \times 3$矩阵的系综平均,发现它们与单位矩阵和相应的标量Minkowski泛函的乘积成比例。我们展示了如何从离散采样场数值重建$W^{0,2}_{1}$和$W^{0,2}_{2}$,并将我们的算法应用于从线性$Λ$ CDM物质功率谱产生的各向同性高斯场。然后,我们引入各向异性通过应用线性红移空间畸变算子的物质密度场,并发现$W^{0,2}_{1}$和$W^{0,2}_{2}$表现出不同的信号,其特征在于它们的对角分量之间的不平等。我们讨论了这个信号的物理起源,以及如何可以用来约束红移空间失真参数$Υ\equiv f/b$。

英文摘要:

We apply the Minkowski tensor statistics to three dimensional Gaussian random fields. Minkowski tensors contain information regarding the orientation and shape of excursion sets, that is not present in the scalar Minkowski functionals. They can be used to quantify globally preferred directions, and additionally provide information on the mean shape of subsets of a field. This makes them ideal statistics to measure the anisotropic signal generated by redshift space distortion in the low redshift matter density field. We review the definition of the Minkowski tensor statistics in three dimensions, focusing on two coordinate invariant quantities $W^{0,2}_{1}$ and $W^{0,2}_{2}$. We calculate the ensemble average of these $3 \times 3$ matrices for an isotropic Gaussian random field, finding that they are proportional to products of the identity matrix and a corresponding scalar Minkowski functional. We show how to numerically reconstruct $W^{0,2}_{1}$ and $W^{0,2}_{2}$ from discretely sampled fields and apply our algorithm to isotropic Gaussian fields generated from a linear $Λ$CDM matter power spectrum. We then introduce anisotropy by applying a linear redshift space distortion operator to the matter density field, and find that both $W^{0,2}_{1}$ and $W^{0,2}_{2}$ exhibit a distinct signal characterised by inequality between their diagonal components. We discuss the physical origin of this signal and how it can be used to constrain the redshift space distortion parameter $Υ\equiv f/b$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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