arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2007.05735astro-ph.CO
收藏

用于组合宇宙学探测器的快速光锥

Fast Lightcones for Combined Cosmological Probes

Raphael Sgier, Janis Fluri, Jörg Herbel, Alexandre Réfrégier, Adam Amara, Tomasz Kacprzak, Andrina Nicola

摘要:

不同宇宙学探测器的组合提供了对$Λ$ CDM模型的严格检验,并增强了对系统学的控制。为此,我们提出了在Sgier等人2019(arXiv:1801.05745)中首次引入的光锥生成器UFalcon的扩展,从而能够模拟不同宇宙学探测器的自洽映射集。每个实现都是从相同的底层模拟密度场生成的,并包含不同探测器的全天空地图,即弱透镜剪切,星系过密度,包括RSD,CMB透镜,和CMB温度各向异性的ISW效应。由UFalcon执行的光锥生成是并行的,并且基于用GPU加速的$N$ -Body代码PkdGrav 3模拟的大周期体积的复制。构建光锥的后处理仅需要大约1个walltime-hour的运行时间,对应于大约100个CPU-hour。我们使用随机化过程来增加准独立的全天空UFalcon地图实现的数量,这使我们能够计算出准确的多探头协方差矩阵。使用这个框架,我们预测宇宙学参数的约束条件进行多探针似然分析相结合的模拟未来阶段IV类调查。我们发现,包括探针之间的互相关显着增加了信息增益的参数约束。我们还发现,使用一个非高斯协方差矩阵是越来越重要的,因为更多的探头和互相关功率谱。一个版本的UFalcon包目前包括弱引力透镜是公开的。

英文摘要:

The combination of different cosmological probes offers stringent tests of the $Λ$CDM model and enhanced control of systematics. For this purpose, we present an extension of the lightcone generator UFalcon first introduced in Sgier et al. 2019 (arXiv:1801.05745), enabling the simulation of a self-consistent set of maps for different cosmological probes. Each realization is generated from the same underlying simulated density field, and contains full-sky maps of different probes, namely weak lensing shear, galaxy overdensity including RSD, CMB lensing, and CMB temperature anisotropies from the ISW effect. The lightcone generation performed by UFalcon is parallelized and based on the replication of a large periodic volume simulated with the GPU-accelerated $N$-Body code PkdGrav3. The post-processing to construct the lightcones requires only a runtime of about 1 walltime-hour corresponding to about 100 CPU-hours. We use a randomization procedure to increase the number of quasi-independent full-sky UFalcon map-realizations, which enables us to compute an accurate multi-probe covariance matrix. Using this framework, we forecast cosmological parameter constraints by performing a multi-probe likelihood analysis for a combination of simulated future stage-IV-like surveys. We find that the inclusion of the cross-correlations between the probes significantly increases the information gain in the parameter constraints. We also find that the use of a non-Gaussian covariance matrix is increasingly important, as more probes and cross-correlation power spectra are included. A version of the UFalcon package currently including weak gravitational lensing is publicly available.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑