论文标题
物质功率谱的协方差包括调查窗口函数效果：N体模拟与网格上的第五阶扰动理论
Covariance of the matter power spectrum including the survey window function effect: N-body simulations vs. fifth-order perturbation theory on grid
论文作者
论文摘要
考虑到调查窗口函数的效果，我们为物质功率谱的协方差矩阵提供了一个近距离的（第五或NNLO）订单计算。使用基于网格的计算方案，用于标准扰动理论GridSPT，我们迅速在扰动理论中将非线性密度字段的多个实现为第五阶，然后估算样品中的功率谱和协方差矩阵。到最后，我们获得了非高斯协方差，源自一环三谱而没有明确计算三光谱。通过将GridSPT计算与N体结果进行比较，我们表明NNLO GridSPT结果在准线性尺度上重现了N-body结果，其中SPT准确地模拟了非线性物质功率谱。将调查窗口函数效应纳入GridSPT非常简单，所得的NNLO协方差矩阵也与N体结果匹配。
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 the GridSPT calculations with the N-body results, we show that NNLO GridSPT result reproduces the N-body results on quasi-linear scales where SPT accurately models nonlinear matter power spectrum. Incorporating the survey window function effect to GridSPT is rather straightforward, and the resulting NNLO covariance matrix also matches well with the N-body results.
