论文标题
银河系在红移空间中偏斜
Galaxy Skew-Spectra in Redshift-Space
论文作者
论文摘要
现代星系调查专注于星系功率谱或2点相关函数，以测试和限制宇宙学模型。其他信息来自高阶N点功能，但它们的分析具有挑战性。一个简单的解决方案是计算平方星系密度和星系密度之间的跨功率。该偏斜光谱易于测量和绘制，具有标准星系功率谱的许多熟悉的有用属性。我们表明，通过计算多个二次字段并将它们与密度相关联，可以用偏斜的光谱捕获对树级红移空间双光谱的所有贡献。使用合成数据集，我们表明我们的测量管道与分析预测相匹配，并且它们对星系偏差参数的依赖性和对数增长率在理论上是预期的。
Modern galaxy surveys focus on the galaxy power spectrum or 2-point correlation function to test and constrain cosmological models. Additional information comes from higher-order N-point functions, but their analysis is challenging. A simple solution is to compute the cross-power spectrum between the squared galaxy density and the galaxy density. Being simple to measure and to plot, this skew-spectrum shares many of the familiar useful properties of the standard galaxy power spectrum. We show that by computing multiple quadratic fields and correlating them with the density, all contributions to the tree-level redshift-space galaxy bispectrum can be captured with skew-spectra. Using synthetic datasets, we show that our measurement pipeline matches analytical predictions, and that their dependence on galaxy bias parameters and the logarithmic growth rate is as expected theoretically.
