论文标题
扰动理论混音：改进的非线性建模超出标准扰动理论
Perturbation Theory Remixed: Improved Nonlinearity Modeling beyond Standard Perturbation Theory
论文作者
论文摘要
我们提出了一种新颖的$ n $ ept（$ n $ th-t阶欧拉扰动理论）方案，以通过扰动理论中的最高$ n $ th级密度字段来对非线性密度字段进行建模。获得的分析功率谱与所有20个深色套件的$ n $体体模拟的结果表现出极好的一致性，这些套件在广泛的宇宙学上传播。该协议比常规的两环标准扰动理论要好得多，并且将达到$ k _ {\ rm max} \ simeq 0.4〜h/{\ rm mpc} $ at $ z = 3 $，对于最适合的Planck宇宙学，没有任何免费参数。该方法可以加速非线性宇宙学密度场的正向建模，这是对宇宙奥秘（例如通货膨胀，暗能量和暗物质）必不可少的探针。
We present a novel $n$EPT ($n$th-order Eulerian Perturbation Theory) scheme to model the nonlinear density field by the summation up to $n$th-order density fields in perturbation theory. The obtained analytical power spectrum shows excellent agreement with the results from all 20 Dark-Quest suites of $N$-body simulations spreading over a broad range of cosmologies. The agreement is much better than the conventional two-loop Standard Perturbation Theory and would reach out to $k_{\rm max}\simeq 0.4~h/{\rm Mpc}$ at $z=3$ for the best-fitting Planck cosmology, without any free parameters. The method can accelerate the forward modeling of the non-linear cosmological density field, an indispensable probe of cosmic mysteries such as inflation, dark energy, and dark matter.
