Real-Time Feynman Path Integral Realization of Instantons

Abstract

In Euclidean path integrals, quantum mechanical tunneling amplitudes are associated with instanton configurations. We explain how tunneling amplitudes are encoded in real-time Feynman path integrals. The essential steps are borrowed from Picard-Lefschetz theory and resurgence theory.

v1, 5 pages, 2 figures. v2: typos fixed, references added

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