Beyond two-point statistics: using the minimum spanning tree as a tool for cosmology
Beyond two-point statistics: using the minimum spanning tree as a tool for cosmology
复制标题
DOI：
10.1093/mnras/stz3075
复制
发表时间：
2019-07
影响因子：
4.8
通讯作者：
K. Naidoo;L. Whiteway;E. Massara;D. Gualdi;O. Lahav;M. Viel;H. Gil-Marín;A. Font-Ribera
中科院分区：
文献类型：
--
作者：
K. Naidoo;L. Whiteway;E. Massara;D. Gualdi;O. Lahav;M. Viel;H. Gil-Marín;A. Font-Ribera
大尺度结构的宇宙学研究依赖于两点统计，没有充分利用宇宙网的丰富结构。在本文中，我们展示了如何使用最小生成树（MST）捕获一些宇宙网信息，首次使用它来估计模拟中的宇宙学参数。暗物质的离散示踪剂（例如星系、N体粒子或晕）被用作节点来构建一个独特的图，即 MST，用于追踪骨骼结构。我们使用一系列 COmoving Lagrangian Acceleration (COLA) 模拟中的光环来研究 MST 对宇宙学参数的依赖性，其盒子大小为 $250\ h^{-1}\, {\rm Mpc}$，改变标量涨落 (As) 的幅度、物质密度 (Ωm) 和中微子质量 (Σmν)。功率谱 P 和双谱 B 是针对 0.125 至 0.5 $h\, {\rm Mpc}^{-1}$ 之间的波数进行测量的，而相应的下限 ∼12.6 $h^{-1}\, {\rm Mpc}$ 则应用于 MST。各个方法的约束相当相似，但结合起来我们可以看到 Ωm 上的 $\sim 17{{\ \rm per\ cent}}$ ($\sim 12{{\ \rm per\ cent}}$) 和 As 上的 $\sim 12{{\ \rm per\ cent}}$ ($\sim 10{{\ \rm per\ cent}}$) 相对于 P (P + B) 的改进 1σ 约束，从而表明 MST 提供了额外的信息。 MST 可应用于 3D 中当前和未来的光谱测量（BOSS、DESI、Euclid、PSF、WFIRST 和 4MOST）以及断层摄影壳中的光度测量（DES 和 LSST），以约束参数和/或测试系统。
Cosmological studies of large-scale structure have relied on two-point statistics, not fully exploiting the rich structure of the cosmic web. In this paper we show how to capture some of this cosmic web information by using the minimum spanning tree (MST), for the first time using it to estimate cosmological parameters in simulations. Discrete tracers of dark matter such as galaxies, N-body particles or haloes are used as nodes to construct a unique graph, the MST, that traces skeletal structure. We study the dependence of the MST on cosmological parameters using haloes from a suite of COmoving Lagrangian Acceleration (COLA) simulations with a box size of $250\ h^{-1}\, {\rm Mpc}$, varying the amplitude of scalar fluctuations (As), matter density (Ωm), and neutrino mass (∑mν). The power spectrum P and bispectrum B are measured for wavenumbers between 0.125 and 0.5 $h\, {\rm Mpc}^{-1}$, while a corresponding lower cut of ∼12.6 $h^{-1}\, {\rm Mpc}$ is applied to the MST. The constraints from the individual methods are fairly similar but when combined we see improved 1σ constraints of $\sim 17{{\ \rm per\ cent}}$ ($\sim 12{{\ \rm per\ cent}}$) on Ωm and $\sim 12{{\ \rm per\ cent}}$ ($\sim 10{{\ \rm per\ cent}}$) on As with respect to P (P + B) thus showing the MST is providing additional information. The MST can be applied to current and future spectroscopic surveys (BOSS, DESI, Euclid, PSF, WFIRST, and 4MOST) in 3D and photometric surveys (DES and LSST) in tomographic shells to constrain parameters and/or test systematics.