RE-CAPTURING COSMIC INFORMATION
RE-CAPTURING COSMIC INFORMATION
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DOI：
10.1088/2041-8205/729/1/l11
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发表时间：
2010-08
期刊：
影响因子：
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通讯作者：
H. Seo;Masanori Sato;S. Dodelson;B. Jain;M. Takada
中科院分区：
文献类型：
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作者：
H. Seo;Masanori Sato;S. Dodelson;B. Jain;M. Takada
可以利用遥远星系的引力透镜来推断会聚场作为天空角位置的函数。这个领域的统计数据，很像宇宙微波背景（CMB）的统计数据，可以用来提取宇宙学中基本参数的信息，尤其是宇宙中的暗能量。与CMB不同，决定收敛场的宇宙物质分布高度非高斯分布，反映了伴随结构形成的非线性过程。因此，标准功率谱测量无法获得包含在初始场中的大部分宇宙信息。本文提出了一种利用观测到的（非线性）收敛场的简单函数的功率谱来重新捕获宇宙信息的方法。我们利用收敛场的修正对数变换，使Neyrinck等人的方法适用于透镜。对数变换场的傅里叶变换具有几乎不相关的模式，这允许从小尺度模式中提取额外的宇宙学信息。
Gravitational lensing of distant galaxies can be exploited to infer the convergence field as a function of angular position on the sky. The statistics of this field, much like that of the cosmic microwave background (CMB), can be studied to extract information about fundamental parameters in cosmology, most notably the dark energy in the universe. Unlike the CMB, the distribution of matter in the universe which determines the convergence field is highly non-Gaussian, reflecting the nonlinear processes that accompanied structure formation. Much of the cosmic information contained in the initial field is therefore unavailable to the standard power spectrum measurements. Here we propose a method for re-capturing cosmic information by using the power spectrum of a simple function of the observed (nonlinear) convergence field. We adapt the approach of Neyrinck et al. to lensing by using a modified logarithmic transform of the convergence field. The Fourier transform of the log-transformed field has modes that are nearly uncorrelated, which allows for additional cosmological information to be extracted from small-scale modes.