论文标题
De Sitter Spacetime中自相互作用标量字段的二阶随机理论
Second-order stochastic theory for self-interacting scalar fields in de Sitter spacetime
论文作者
论文摘要
我们在Sitter Spacetime中引入了用于轻标量场的二阶随机有效理论，从而将随机方法的有效性扩展到了无质量极限之外，并证明了如何用于非驱动的长距离相关功能。二阶随机理论的参数是通过扰动计算确定的，如果自我交互参数$λ$满足$λ\ ll m^2/h^2 $，则$ h $是标量，而$ h $是hubble率，则有效。因此，它允许比常规扰动理论更强大，该理论仅限于$λ\ ll m^4/h^4 $，而红外发散。我们通过将其结果与扰动量子场理论进行比较并缩短了随机计算，并通过对其参数进行完整的一环计算来讨论提高其准确性的前景，从而证明了二阶随机理论的适用性。
We introduce a second-order stochastic effective theory for light scalar fields in de Sitter spacetime, extending the validity of the stochastic approach beyond the massless limit and demonstrating how it can be used to compute long-distance correlation functions non-perturbatively. The parameters of the second-order stochastic theory are determined from quantum field theory through a perturbative calculation, which is valid if the self-interaction parameter $λ$ satisfies $λ\ll m^2/H^2$, where $m$ is the scalar and $H$ is the Hubble rate. Therefore it allows stronger self-interactions than conventional perturbation theory, which is limited to $λ\ll m^4/H^4$ by infrared divergences. We demonstrate the applicability of the second-order stochastic theory by comparing its results with perturbative quantum field theory and overdamped stochastic calculations, and discuss the prospects of improving its accuracy with a full one-loop calculation of its parameters.
