The peculiar velocities of biased tracers of the cosmic density field contain important information about the growth of large scale structure and generate anisotropy in the observed clustering of galaxies. Using N-body data, we show that velocity expansions for halo redshift-space power spectra are converged at the percent-level at perturbative scales for most line-of-sight angles $\mu$ when the first three pairwise velocity moments are included, and that the third moment is well-approximated by a counterterm-like contribution. We compute these pairwise-velocity statistics in Fourier space using both Eulerian and Lagrangian one-loop perturbation theory using a cubic bias scheme and a complete set of counterterms and stochastic contributions. We compare the models and show that our models fit both real-space velocity statistics and redshift-space power spectra for both halos and a mock sample of galaxies at sub-percent level on perturbative scales using consistent sets of parameters, making them appealing choices for the upcoming era of spectroscopic, peculiar-velocity and kSZ surveys.

中文翻译：

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单环微扰理论中速度统计和红移空间畸变的一致建模

宇宙密度场偏向示踪剂的特殊速度包含有关大尺度结构生长的重要信息，并在观测到的星系团中产生各向异性。使用 N 体数据，我们表明，当包括前三个成对速度矩时，光晕红移空间功率谱的速度扩展在大多数视线角 $\mu$ 的微扰尺度上收敛于百分比水平，并且三阶矩通过类似反项的贡献很好地近似。我们使用欧拉和拉格朗日单环微扰理论，使用三次偏置方案和一组完整的反项和随机贡献计算傅立叶空间中的这些成对速度统计。