论文标题
重新归一化的单点概率分布函数的宇宙学计数
Renormalizing one-point probability distribution function for cosmological counts in cells
论文作者
论文摘要
我们研究了在球形细胞上平均物质密度的单点概率分布函数（PDF）。 PDF的领先部分是由球形崩溃动力学定义的，而次要领导的部分来自鞍点解决方案周围波动的集成。后一个计算从短模式中获得相当大的贡献，必须重新归一化。我们通过对短扰动的有效应激张量进行建模，提出了一种新的重新归一化方法。该模型包含三个免费参数。其中两个与单循环物质功率谱和双光谱中的对抗有关，其中一个更多参数化了其红移依赖性。这种关系可用于将模型拟合到PDF数据中。我们以高分辨率N体模拟的结果面对模型，并在所有红移中找到了Cell Radii $ r _*\ geq 10 \，{\ rm mpc}/h $的出色一致性。以$ r _*\ leq 10 \，{\ rm mpc}/h $在低红移时检测到以百分之几的差异，并与模型的两环校正相关联。
We study the one-point probability distribution function (PDF) for matter density averaged over spherical cells. The leading part to the PDF is defined by spherical collapse dynamics, whereas the next-to-leading part comes from the integration over fluctuations around the saddle-point solution. The latter calculation receives sizable contributions from short modes and must be renormalized. We propose a new approach to renormalization by modeling the effective stress-energy tensor for short perturbations. The model contains three free parameters. Two of them are related to the counterterms in the one-loop matter power spectrum and bispectrum, one more parameterizes their redshift dependence. This relation can be used to impose priors in fitting the model to the PDF data. We confront the model with the results of high-resolution N-body simulations and find excellent agreement for cell radii $r_*\geq 10\,{\rm Mpc}/h$ at all redshifts down to $z=0$. Discrepancies at a few per cent level are detected at low redshifts for $r_*\leq 10\,{\rm Mpc}/h$ and are associated with two-loop corrections to the model.
