Weak Lensing: Prospects for Measuring Cosmological Parameters
Weak Lensing: Prospects for Measuring Cosmological Parameters
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DOI：
10.1086/311947
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发表时间：
1998-11
期刊：
影响因子：
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通讯作者：
Wayne Hu;M. Tegmark
中科院分区：
文献类型：
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作者：
Wayne Hu;M. Tegmark
大尺度结构对星系的弱透镜效应有可能像测量宇宙微波背景辐射（CMB）一样精确地测量宇宙学量。然而，观测量和基本参数之间的关系是更加复杂和退化，特别是在绝热冷暗物质模型考虑这里的全空间。我们介绍了一个Fisher矩阵分析弱透镜调查中包含的信息来解决这些问题，并提供了一个简单的方法来估计调查属性和源红移的不确定性如何影响参数测量。我们发现，度尺度及以上的调查可以提高精度的参数，影响增长率的结构相比，单独使用CMB的数量级，即使特征红移的来源必须从数据本身确定。令人惊讶的是，稀疏采样和增加源红移都可以削弱宇宙学约束。
Weak lensing of galaxies by large-scale structure can potentially measure cosmological quantities as accurately as the cosmic microwave background (CMB). However, the relation between observables and fundamental parameters is more complex and degenerate, especially in the full space of adiabatic cold dark matter models considered here. We introduce a Fisher matrix analysis of the information contained in weak-lensing surveys to address these issues and provide a simple means of estimating how survey properties and source redshift uncertainties affect parameter measurement. We find that surveys on degree scales and above can improve the accuracy on parameters that affect the growth rate of structure by up to an order of magnitude compared to using the CMB alone, even if the characteristic redshift of the sources must be determined from the data itself. Surprisingly, both sparse sampling and increasing the source redshift can weaken the cosmological constraints.