Regularized cosmological power spectrum and correlation function in modified gravity models
Regularized cosmological power spectrum and correlation function in modified gravity models
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修正引力模型中的正则宇宙功率谱和相关函数
DOI：
10.1103/physrevd.90.123515
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发表时间：
2014
影响因子：
5
通讯作者：
Kazuya Koyama
中科院分区：
文献类型：
--
作者：
Atsushi Taruya;Takahiro Nishimichi;Francis Bernardeau;Takashi Hiramatsu;Kazuya Koyama
基于多点传播子展开，给出了修正引力背景下宇宙功率谱和相关函数的恢复微扰计算。在一类具有筛选机制的修正引力模型中，我们应用eikonal近似推导了恢复传播子的控制方程，该方程部分地包含了高极限中的非摄动效应。在高极限处产生的传播子包含了由筛分机制和标准指数阻尼产生的新修正。我们明确地推导了特定修正重力模型中新的高贡献的表达式，并发现在重力情况下，对于当前约束的模型参数，修正基本上是次导阶的，可以忽略。因此，在重力情况下，与GR情况类似，我们可以解析地构造正则化传播子，该传播子既可以再现恢复的高行为，也可以再现用标准摄动理论计算的低结果，并始终考虑到在大尺度上有效的重力的非线性修正。利用正则化多点传播算子，给出了单环阶的功率谱和相关函数的预测，并与重力模型下的体模拟结果进行了比较。作为一个重要的应用，我们还讨论了红移空间畸变，并计算了各向异性功率谱和相关函数。
Based on the multipoint propagator expansion, we present resummed perturbative calculations for cosmological power spectra and correlation functions in the context of modified gravity. In a wide class of modified gravity models that have a screening mechanism to recover general relativity (GR) on small scales, we apply the eikonal approximation to derive the governing equation for resummed propagator that partly includes the nonperturbative effect in the high-limit. The resultant propagator in the high-limit contains the new corrections arising from the screening mechanism as well as the standard exponential damping. We explicitly derive the expression for new high-contributions in specific modified gravity models, and find that in the case ofgravity for a currently constrained model parameter, the corrections are basically of the subleading order and can be neglected. Thus, ingravity, similarly to the GR case, we can analytically construct the regularized propagator that reproduces both the resummed high-behavior and the low-results computed with standard perturbation theory, consistently taking account of the nonlinear modification of gravity valid at large scales. With the regularized multipoint propagators, we give predictions for power spectrum and correlation function at one-loop order, and compare those with-body simulations ingravity model. As an important application, we also discuss the redshift-space distortions and compute the anisotropic power spectra and correlation functions.