  We propose a simple non-perturbative formalism for false vacuum decay using
functional methods. We introduce the quasi-stationary effective action, a
bounce action that non-perturbatively incorporates radiative corrections and is
robust to strong couplings. The quasi-stationary effective action obeys an
exact flow equation in a modified functional renormalization group with a
motivated regulator functional. We demonstrate the use of this formalism in a
simple toy model and compare our result with that obtained in perturbation
theory.
