论文标题
大规模结构的渐近扩展
Asymptotic expansions for the Large Scale Structure
论文作者
论文摘要
我们探索功率谱（PS）的深紫外线（即短途）和以冷暗物质为主导的宇宙的相关功能的极限。虽然对于大尺度，PS可以写为双系列扩展，在线性PS和Wavenumber $ k $的能力中，我们表明，在相反的限制中，它可以通过$ 1/k^{d+2n} $的功能的扩展来表示，在$ 1/k^{d+2n} $中，$ d $是$ d $的$ d $，而不是$ n $ $ n $ n non not ins a a。扩展术语的系数在线性PS中是非扰动的，可以根据位移场的概率密度函数来解释，并围绕我们识别的后者的特定配置进行评估。在Zel'Dovich动力学的情况下，可以通过分析确定这些系数，而对于确切的动力学，它们可以被视为拟合或滋扰参数。我们通过数值模拟确认了我们的发现，并讨论了与较大尺度和实际测量结果相匹配的结果的必要步骤。
We explore the deep ultraviolet (that is, short-distance) limit of the power spectrum (PS) and of the correlation function of a cold dark matter dominated Universe. While for large scales the PS can be written as a double series expansion, in powers of the linear PS and of the wavenumber $k$, we show that, in the opposite limit, it can be expressed via an expansion in powers of the form $1/k^{d+2n}$, where $d$ is the number of spatial dimensions, and $n$ is a non negative integer. The coefficients of the terms of the expansion are nonperturbative in the linear PS, and can be interpreted in terms of the probability density function for the displacement field, evaluated around specific configurations of the latter, that we identify. In the case of the Zel'dovich dynamics, these coefficients can be determined analytically, whereas for the exact dynamics they can be treated as fit, or nuisance, parameters. We confirm our findings with numerical simulations and discuss the necessary steps to match our results to those obtained for larger scales and to actual measurements.
