Covariance of the matter power spectrum including the survey window function effect: N -body simulations versus fifth-order perturbation theory on grids
Covariance of the matter power spectrum including the survey window function effect: N -body simulations versus fifth-order perturbation theory on grids
复制标题
物质功率谱的协方差，包括测量窗函数效应：N 体模拟与网格上的五阶微扰理论
DOI：
10.1103/physrevd.103.023501
复制
发表时间：
2021
影响因子：
5
通讯作者：
Jeong Donghui
中科院分区：
文献类型：
--
作者：
Taruya Atsushi;Nishimichi Takahiro;Jeong Donghui
我们提出了一个次到次到领先（五阶或NNLO）计算的协方差矩阵的物质功率谱，考虑到调查窗口函数的影响。利用标准微扰理论的网格计算方法GridSPT，快速生成微扰理论中五阶非线性密度场的多重实现，然后从样本中估计功率谱和协方差矩阵。最后，我们得到了非高斯协方差起源于单圈三谱没有显式计算的三谱。通过比较GridSPT计算与体的结果，我们表明，NNLOGridSPT结果再现体的结果在准线性尺度上，其中SPT准确地模拟非线性物质的功率谱。将调查窗口函数效应表示为GridSPT相当简单，并且得到的NNLO协方差矩阵也与身体结果匹配良好。
We present a next-to-next-to-leading (fifth or NNLO) order calculation for the covariance matrix of the matter power spectrum, taking into account the effect of survey window functions. Using the grid-based calculation scheme for the standard perturbation theory,GridSPT, we quickly generate multiple realizations of the nonlinear density fields to fifth order in perturbation theory, then estimate the power spectrum and the covariance matrix from the sample. To the end, we have obtained the non-Gaussian covariance originated from the one-loop trispectrum without explicitly computing the trispectrum. By comparing theGridSPTcalculations with the-body results, we show that NNLOGridSPTresult reproduces the-body results on quasilinear scales, where SPT accurately models nonlinear matter power spectrum. Incorporating the survey window function effect toGridSPTis rather straightforward, and the resulting NNLO covariance matrix also matches well with the-body results.