Diagrammatic Monte Carlo simulation of non-equilibrium systems
  We generalize the recently developed diagrammatic Monte Carlo techniques for quantum impurity models from an imaginary time to a Keldysh formalism suitable for real-time and nonequilibrium calculations. Both weak-coupling and strong-coupling based methods are introduced, analysed and applied to the study of transport and relaxation dynamics in interacting quantum dots. 
Philipp Werner, Takashi Oka, and Andrew J. Millis