Normalizing flows and the real-time sign problem
Normalizing flows and the real-time sign problem
复制标题
标准化流量和实时符号问题
DOI：
10.1103/physrevd.103.114509
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发表时间：
2021
影响因子：
5
通讯作者：
Y. Yamauchi
中科院分区：
文献类型：
--
作者：
S. Lawrence;Y. Yamauchi
归一化flOW最近被应用于格子fi场理论中的加速马氏链问题。我们提出了归一化flOW的一个推广，允许它们应用于具有符号问题的理论。这些复杂的归一化flOW与过去应用于符号问题的轮廓变形(即广义Lefschetz顶针方法)密切相关。我们讨论了正规化flOW的存在性问题：它们在最一般的情况下不存在，但我们认为精确正规化flOW可能存在于许多有趣的物理问题，包括Lefschetz顶针分解具有难以处理的符号问题的情况。最后，可以用微扰理论构造归一化的flOW。对于与0+1维实标量ff场有关的Schwinger-Keldysh符号问题，我们给出了它们在一系列耦合范围内的e-fi效应的数值结果。
Normalizing flows have recently been applied to the problem of accelerating Markov chains in lattice field theory. We propose a generalization of normalizing flows that allows them to applied to theories with a sign problem. These complex normalizing flows are closely related to contour deformations (i.e. the generalized Lefschetz thimble method), which been applied to sign problems in the past. We discuss the question of the existence of normalizing flows: they do not exist in the most general case, but we argue that exact normalizing flows are likely to exist for many physically interesting problems, including cases where the Lefschetz thimble decomposition has an intractable sign problem. Finally, normalizing flows can be constructed in perturbation theory. We give numerical results on their effectiveness across a range of couplings for the Schwinger-Keldysh sign problem associated to a real scalar field in 0 + 1 dimensions.