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arXiv 2212.09799astro-ph.COhep-phhep-th
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宇宙学细胞计数的单点概率分布函数的重整化

Renormalizing one-point probability distribution function for cosmological counts in cells

Anton Chudaykin, Mikhail M. Ivanov, Sergey Sibiryakov

AI总结:

本文提出一种通过建模短扰动有效应力-能量张量来重整化宇宙密度单点PDF的新方法,并用N体模拟验证了其在较大细胞半径下的准确性。

摘要:

我们研究了球状细胞内平均物质密度的单点概率分布函数(PDF)。PDF的主导部分由球对称坍缩动力学定义,而次主导部分来自对鞍点解周围涨落的积分。后者的计算受到短波模的显著贡献,必须进行重整化。我们提出了一种新的重整化方法,通过为短扰动建模有效应力-能量张量来实现。该模型包含三个自由参数。其中两个与单圈物质功率谱和双谱中的抵消项相关,另一个参数化它们的红移依赖性。这一关系可用于在将模型拟合到PDF数据时施加先验。我们将模型与高分辨率N体模拟的结果进行对比,发现对于所有红移到z=0,在细胞半径$r_*\geq 10\\,{\rm Mpc}/h$下具有极好的一致性。在低红移下,对于$r_*\leq 10\\,{\rm Mpc}/h$检测到百分之几水平的差异,这与模型的双圈修正有关。

英文摘要:

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.

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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