A new algorithm for calculating the curvature perturbations in stochastic inflation
A new algorithm for calculating the curvature perturbations in stochastic inflation
复制标题
计算随机暴胀曲率扰动的新算法
DOI：
10.1088/1475-7516/2013/12/036
复制
发表时间：
2013
影响因子：
6.4
通讯作者：
Y. Tada and T. Takesako
中科院分区：
文献类型：
--
作者：
T. Fujita;M. Kawasaki;Y. Tada and T. Takesako
我们提出了一种新的方法来计算曲率扰动过程中产生的通货膨胀的随机形式主义。在我们的形式中，e-折叠的涨落是直接计算的，而不需要对暴胀子场进行微扰展开，并且通过δN形式将它们与曲率微扰联系起来。结果自动地包括高阶扰动的贡献，因为我们非微扰地求解运动方程。本文从理论上证明了我们的结果（功率谱和非线性参数）与单场慢卷暴胀的标准结果是一致的。我们还描述了更一般的暴胀模型中曲率扰动的数值计算算法。
We propose a new approach for calculating the curvature perturbations produced during inflation in the stochastic formalism. In our formalism, the fluctuations of the e-foldings are directly calculated without perturbatively expanding the inflaton field and they are connected to the curvature perturbations by the δN formalism. The result automatically includes the contributions of the higher order perturbations because we solve the equation of motion non-perturbatively. In this paper, we analytically prove that our result (the power spectrum and the nonlinearity parameter) is consistent with the standard result in single field slow-roll inflation. We also describe the algorithm for numerical calculations of the curvature perturbations in more general inflation models.