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arXiv 1302.4533astro-ph.CO
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从微扰理论的拉格朗日空间正则化得到的物质功率谱

Matter power spectrum from a Lagrangian-space regularization of perturbation theory

Patrick Valageas, Takahiro Nishimichi, Atsushi Taruya

摘要:

我们提出了一种新的方法来计算物质密度功率谱,从大的线性尺度到小的高度非线性尺度。而不是明确计算的一部分系列的高阶图,在微扰再确认计划,我们嵌入一个现实的非线性拉格朗日空间anomaly的标准微扰理论。我们还指出,一个“粘附”正则化的壳交叉制度是更现实的比“Zel'dovich”的行为,粒子自由地逃逸到无穷大。这提供了一个具有良好小尺度特性的“宇宙网”功率谱,在轻度非线性尺度上提供了与晕轮模型的良好匹配。我们得到了很好的协议与数值模拟在大尺度上,优于3%的$k\leq 1 h$ Mpc $^{-1}$,和在小尺度上,优于10%的$k \leq 10 h$ Mpc $^{-1}$,在$z \geq 0.35$,这改善了以前的方法。

英文摘要:

We present a new approach to computing the matter density power spectrum, from large linear scales to small highly nonlinear scales. Instead of explicitly computing a partial series of high-order diagrams, as in perturbative resummation schemes, we embed the standard perturbation theory within a realistic nonlinear Lagrangian-space ansatz. We also point out that an "adhesion-like" regularization of the shell-crossing regime is more realistic than a "Zel'dovich-like" behavior, where particles freely escape to infinity. This provides a "cosmic web" power spectrum with good small-scale properties that provide a good matching with a halo model on mildly nonlinear scales. We obtain a good agreement with numerical simulations on large scales, better than 3% for $k\leq 1 h$Mpc$^{-1}$, and on small scales, better than 10% for $k \leq 10 h$Mpc$^{-1}$, at $z \geq 0.35$, which improves over previous methods.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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