In modern cosmology, the precision of the theoretical prediction is increasingly required. In cosmological [Formula: see text]-body simulations, the effect of higher-order Lagrangian perturbation on the initial conditions appears in terms of statistical quantities of matter density field. We have considered the effect of third-order Lagrangian perturbation theory (3LPT) on the initial conditions, which can be applied to Gadget-2 code. Then, as statistical quantities, non-Gaussianity of matter density field has been compared between cases of different order perturbations for the initial conditions. Then, we demonstrate the validity of the initial conditions with second-order Lagrangian perturbation theory (2LPT).

中文翻译：

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N 体模拟中基于拉格朗日微扰理论的初始条件瞬态 III：Gadget-2 代码案例

在现代宇宙学中，对理论预测的精度要求越来越高。在宇宙学[公式：见正文]-体模拟中，高阶拉格朗日扰动对初始条件的影响表现为物质密度场的统计量。我们已经考虑了三阶拉格朗日微扰理论 (3LPT) 对初始条件的影响，可以将其应用于 Gadget-2 代码。然后，作为统计量，比较了初始条件下不同阶摄动情况下物质密度场的非高斯性。然后，我们用二阶拉格朗日摄动理论（2LPT）证明了初始条件的有效性。