Schwinger Mechanism with Stochastic Quantization
  We prescribe a formulation of the particle production with real-time Stochastic Quantization. To construct the retarded and the time-ordered propagators we decompose the stochastic variables into positive- and negative-energy parts. In this way we demonstrate how to derive a standard formula for the Schwinger mechanism under time-dependent electric fields. We discuss a mapping to the Schwinger-Keldysh formalism and a relation to the classical statistical simulation. 
Kenji Fukushima and Tomoya Hayata
hep-th cond-mat.other hep-ph