The hand-made tail: non-perturbative tails from multifield inflation
The hand-made tail: non-perturbative tails from multifield inflation
复制标题
DOI：
10.1007/jhep05(2022)052
复制
发表时间：
2021-12
影响因子：
5.4
通讯作者：
A. Achúcarro;Sebastián Céspedes;A. Davis;G. Palma
中科院分区：
文献类型：
--
作者：
A. Achúcarro;Sebastián Céspedes;A. Davis;G. Palma
越来越清楚的是，受概率分布尾部控制的原始曲率场的大而罕见的波动可能会对宇宙当前的结构产生巨大的影响，例如通过原始黑洞。然而，使用标准微扰理论来研究暴胀过程中波动的演化，无法可靠地描述非线性相互作用如何导致非高斯尾。本文利用随机暴胀理论研究了多场涨落对原初曲率场统计性质的非微扰效应。从描述多场涨落的有效作用出发，我们计算了联合概率密度函数，并表明增强的非高斯尾是具有额外自由度的慢卷暴胀的一般特征。
It is becoming increasingly clear that large but rare fluctuations of the primordial curvature field, controlled by the tail of its probability distribution, could have dramatic effects on the current structure of the universe—eg via primordial black-holes. However, the use of standard perturbation theory to study the evolution of fluctuations during inflation fails in providing a reliable description of how non-linear interactions induce non-Gaussian tails. Here, we use the stochastic inflation formalism to study the non-perturbative effects from multi-field fluctuations on the statistical properties of the primordial curvature field. Starting from the effective action describing multi-field fluctuations, we compute the joint probability density function and show that enhanced non-Gaussian tails are a generic feature of slow-roll inflation with additional degrees of freedom.