Normalizing flows and the real-time sign problem

Normalizing flows have recently been applied to the problem of accelerating Markov chains in lattice field theory. We propose a generalization normalizing that allows them theories with sign problem. These complex are closely related contour deformations (i.e., generalized Lefschetz thimble method), which problems past. discuss question existence flows; they do not exist most general case, but we argue exact likely for many physically interesting problems, including cases where decomposition has an intractable Finally, can be constructed perturbation give numerical results on their effectiveness across range couplings Schwinger-Keldysh associated real scalar $0+1$ dimensions.