论文标题
重建后红移空间物质功率谱的协方差
Covariance of the redshift-space matter power spectrum after reconstruction
论文作者
论文摘要
我们探讨了标准密度场重建后红移空间物质功率谱的协方差。我们在树级秩序下得出协方差的扰动公式，并发现来自Triseptrum的非对角线成分的幅度通过重建而降低。使用大量的N体模拟，我们还发现了与前构造的光谱相比，与后重建（后REC）功率光谱的信噪比（S/N）相似，从而相似的离子分量相似，从而显着增加了信噪比（S/N）。这表明泄漏到高阶统计信息的信息通过重建回到了两点统计。有趣的是，当以高斯协方差的线性光谱比线性光谱具有更高的S/N时，当以移位场的平滑尺度为特征的重建尺度低于〜10mpc/h，而三光谱为负。我们证明，从红移空间物质功率谱的单极和四极组件估计的增长率的误差可通过重建显着提高。即使考虑到超级样本协方差，我们也发现增长率有类似的提高，而重建无法纠正超级样本模式的现场变化。
We explore the covariance of redshift-space matter power spectra after a standard density-field reconstruction. We derive perturbative formula of the covariance at the tree-level order and find that the amplitude of the off-diagonal components from the trispectrum decreases by reconstruction. Using a large set of N-body simulations, we also find the similar reduction of the off-diagonal components of the covariance and thereby the signal-to-noise ratio (S/N) of the post-reconstructed (post-rec) power spectra significantly increases compared to the pre-reconstructed spectra. This indicates that the information leaking to higher-order statistics come back to the two-point statistics by reconstruction. Interestingly, the post-rec spectra have higher S/N than the linear spectrum with Gaussian covariance when the scale of reconstruction characterized with the smoothing scale of the shift field is below ~10Mpc/h where the trispectrum becomes negative. We demonstrate that the error of the growth rate estimated from the monopole and quadrupole components of the redshift-space matter power spectra significantly improves by reconstruction. We also find a similar improvement of the growth rate even when taking into account the super-sample covariance, while the reconstruction cannot correct for the field variation of the super-sample modes.
