论文标题
功率谱,双光谱,光晕,空隙及其交叉协方差的超级样本协方差
Super-sample covariance of the power spectrum, bispectrum, halos, voids, and their cross covariances
论文作者
论文摘要
我们研究超级样本协方差(SSC)对功率谱和高阶统计的影响:双光谱,光环质量函数和空隙尺寸函数。我们还研究了SSC对统计数据之间交叉协方差的影响。我们考虑物质和光环田。大规模结构的高阶统计数据包含功率谱以外的其他宇宙学信息,并且是限制宇宙学的强大工具。它们是持续和即将进行的高精度宇宙学调查(例如Desi,PFS,Rubin天文台LSST,Euclid,Spherex,Ska和Roman Space望远镜)的有前途的探测。用于建模和验证这些统计数据的宇宙学模拟通常具有比观察到的宇宙小得多的大小。比模拟框(称为超级样本模式)大的尺度上的密度波动不会被模拟捕获,进而导致协方差矩阵中的不准确性。我们比较了使用包含超级样本模式的模拟框与没有的仿真框进行比较的协方差。我们还与单独的宇宙方法进行了比较。我们发现,虽然功率谱,双光谱和光晕质量函数显示出显着的尺度或质量依赖性SSC,但空隙尺寸函数显示出相对较小的SSC。我们还发现SSC对不同统计数据之间的交叉协方差的贡献很大,这意味着未来的联合分析将需要仔细考虑SSC的影响。为了进一步研究SSC,我们的模拟已在https://github.com/halfdomesims/ssc上公开提供。
We study the effect of super-sample covariance (SSC) on the power spectrum and higher-order statistics: bispectrum, halo mass function, and void size function. We also investigate the effect of SSC on the cross covariance between the statistics. We consider both the matter and halo fields. Higher-order statistics of the large-scale structure contain additional cosmological information beyond the power spectrum and are a powerful tool to constrain cosmology. They are a promising probe for ongoing and upcoming high precision cosmological surveys such as DESI, PFS, Rubin Observatory LSST, Euclid, SPHEREx, SKA, and Roman Space Telescope. Cosmological simulations used in modeling and validating these statistics often have sizes that are much smaller than the observed Universe. Density fluctuations on scales larger than the simulation box, known as super-sample modes, are not captured by the simulations and in turn can lead to inaccuracies in the covariance matrix. We compare the covariance measured using simulation boxes containing super-sample modes to those without. We also compare with the Separate Universe approach. We find that while the power spectrum, bispectrum and halo mass function show significant scale- or mass-dependent SSC, the void size function shows relatively small SSC. We also find significant SSC contributions to the cross covariances between the different statistics, implying that future joint-analyses will need to carefully take into consideration the effect of SSC. To enable further study of SSC, our simulations have been made publicly available at https://github.com/HalfDomeSims/ssc.