The DESI N-body Simulation Project II: Suppressing Sample Variance with Fast Simulations
The DESI N-body Simulation Project II: Suppressing Sample Variance with Fast Simulations
复制标题
DESI N 体仿真项目 II：通过快速仿真抑制样本方差
DOI：
10.1093/mnras/stac1501
复制
发表时间：
2022
影响因子：
4.8
通讯作者：
C. Poppett
中科院分区：
文献类型：
--
作者：
Z. Ding;C. Chuang;Yung;L. Garrison;Adrian E Bayer;Yu Feng;C. Modi;D. Eisenstein;M. White;A. Variu;Cheng Zhao;Hanyu Zhang;Jennifer Meneses Rizo;D. Brooks;K. Dawson;P. Doel;E. Gaztañaga;R. Kehoe;A. Krolewski;M. Landriau;N. Palanque;C. Poppett
暗能量光谱仪（DESI）将为我们的宇宙构建一个大而精确的3D地图。测量有效体积达到1020 h−3Gpc3。这是一个巨大的挑战，准备高分辨率的模拟与更大的体积验证DESI分析管道。AbacusSummit是一套高分辨率的纯暗物质模拟系统，其基础宇宙学模型为200 h−3Gpc3（10倍DESI体积）。然而，还需要做出进一步的努力来提供更精确的数据分析并涵盖其他宇宙学。最近，CARPool方法被提出来使用成对的精确和近似模拟，以有限数量的高分辨率模拟来实现高统计精度。依靠这种技术，我们建议使用快速准N体求解器结合准确的模拟，以产生准确的汇总统计。这使我们能够在我们感兴趣的尺度上获得比预期DESI统计方差小100倍的方差，例如，k < 0.3hMpc−1的晕圈功率谱。此外，它可以显着抑制晕双谱的样本方差。我们进一步推广的方法，只有一个实现在AbacusSummit套件的其他宇宙学，以扩大有效体积20倍。总之，我们提出的战略相结合的高保真度模拟与快速近似的重力求解器和一系列的方差抑制技术设置的路径，一个强大的宇宙学分析的星系调查数据。
Dark Energy Spectroscopic Instrument (DESI) will construct a large and precise 3D map of our Universe. The survey effective volume reaches ∼ 20 h−3Gpc3. It is a great challenge to prepare high-resolution simulations with a much larger volume for validating the DESI analysis pipelines. AbacusSummit is a suite of high-resolution dark-matter-only simulations designed for this purpose, with 200 h−3Gpc3 (10 times DESI volume) for the base cosmology. However, further efforts need to be done to provide more precise analysis of the data and to cover also other cosmologies. Recently, the CARPool method was proposed to use paired accurate and approximate simulations to achieve high statistical precision with a limited number of high-resolution simulations. Relying on this technique, we propose to use fast quasi-N-body solvers combined with accurate simulations to produce accurate summary statistics. This enables us to obtain 100 times smaller variance than the expected DESI statistical variance at the scales we are interested in, e.g., k < 0.3hMpc−1 for the halo power spectrum. In addition, it can significantly suppress the sample variance of the halo bispectrum. We further generalize the method for other cosmologies with only one realization in AbacusSummit suite to extend the effective volume ∼20 times. In summary, our proposed strategy of combining high fidelity simulations with fast approximate gravity solvers and a series of variance suppression techniques sets the path for a robust cosmological analysis of galaxy survey data.