Measuring Primordial Non-Gaussianity in the Cosmic Microwave Background
Measuring Primordial Non-Gaussianity in the Cosmic Microwave Background
复制标题
测量宇宙微波背景中的原初非高斯性
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Benjamin Dan Wandelt
中科院分区：
文献类型：
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作者：
E. Komatsu;D. Spergel;Benjamin Dan Wandelt
我们推导出一种快速的方法来测量原始的非高斯性在一个几乎全天空的宇宙微波背景图。我们发现了一个三次组合的天空地图结合双谱配置捕获一个二次项原始波动。我们的方法只需要N3/2的操作，而不是N5/2，采取的双谱分析（1000倍的速度为l = 512），保持相同的灵敏度。一个关键的组成部分是底层原始波动的地图，它可能比温度地图对原始非高斯性更敏感。我们还得到了一个快速和准确的统计测量非高斯信号从前景点源。该统计比全双谱分析快106倍，可用于估计污染源。我们的算法已成功地应用于威尔金森微波各向异性探测器的天空地图的小松和同事。
We derive a fast way for measuring primordial non-Gaussianity in a nearly full-sky map of the cosmic microwave background. We find a cubic combination of sky maps combining bispectrum configurations to capture a quadratic term in primordial fluctuations. Our method takes only N3/2 operations rather than N5/2, as taken by the bispectrum analysis (1000 times faster for l = 512), retaining the same sensitivity. A key component is a map of the underlying primordial fluctuations, which can be more sensitive to the primordial non-Gaussianity than a temperature map. We also derive a fast and accurate statistic for measuring non-Gaussian signals from foreground point sources. The statistic is 106 times faster than the full bispectrum analysis and can be used to estimate contamination from the sources. Our algorithm has been successfully applied to the Wilkinson Microwave Anisotropy Probe sky maps by Komatsu and coworkers.