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Weak lensing probes of primordial non-Gaussianity and mass estimators of weak-lensing clusters

原初非高斯性的弱透镜探针和弱透镜团的质量估计器

基本信息

批准号：
170603556
负责人：
Dr. Laura Marian, Ph.D.
金额：
--
依托单位：
Department of Physics and Astronomy
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2013-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/170603556?language=en
关键词：
Weak lensing probes primordial non

项目摘要

Weak gravitational lensing (WL) is one of the prime tools to determine the cosmological parameters describing the universe. In particular, it can measure the equation of state of Dark Energy, and it can also be used to test General Relativity. This proposal suggests two lines of investigation, particularly useful in view of the short- and long-term upcoming lensing surveys. The first line addresses the potential of WL surveys to measure primordial non-Gaussianity. We shall use the Fisher matrix formalism to establish which WL observables are suited for this task. These observables will then be measured in shear maps obtained by ray-tracing through numerical simulations of structure formation. The simulations are ‘state-of-the-art’ and have been evolved with both Gaussian and non-Gaussian initial conditions. Thus, it will be possible to probe numerically the sensitivity of WL observables to primordial non-Gaussianity. Among the observables that will be tested and combined are shear peaks, the shear power spectrum, and the shear bispectrum. This study is innovative on several counts, and should yield results that will be useful for future surveys.The second line of research is a full exploration of the cosmological information carried by shear peaks. The 2- and 3-point correlation functions of the shear peaks, as well as the cross-correlation of shear peaks and the shear field have not yet been explored for cosmological constraints. We shall study them both theoretically and in WL maps, and we shall also assess their sensitivity to primordial non-Gaussianity. The other major goal is to give a theoretical prediction for the shear-peak function, also backed up by numerical measurements.

弱引力透镜是确定描述宇宙的宇宙学参数的主要工具之一。特别是，它可以测量暗能量的状态方程，也可以用来检验广义相对论。这一建议提出了两条调查路线，特别是在短期和长期即将到来的透镜调查。第一行讨论了WL调查测量原始非高斯性的潜力。我们将使用Fisher矩阵形式来确定哪些WL观测量适合于这项任务。这些可观的，然后将被测量的剪切映射通过射线追踪获得的结构形成的数值模拟。模拟是“最先进的”，并已演变与高斯和非高斯初始条件。因此，它将有可能探测数值的WL观测原始非高斯的敏感性。将被测试和组合的可观测量包括剪切峰值、剪切功率谱和剪切双谱。这项研究在几个方面都是创新的，应该会产生对未来调查有用的结果。第二条研究路线是全面探索剪切峰所携带的宇宙学信息。剪切峰的2点和3点相关函数，以及剪切峰和剪切场的互相关尚未被探索宇宙学约束。我们将从理论上和在WL地图中研究它们，并且我们还将评估它们对原始非高斯性的敏感性。另一个主要目标是给出剪切峰函数的理论预测，也得到了数值测量的支持。