  We present a path-integral bosonization approach for systems out of
equilibrium based on a duality transformation of the original Dirac fermion
theory combined with the Schwinger-Keldysh time closed contour technique, to
handle the non-equilibrium situation. The duality approach to bosonization that
we present is valid for $D \geq 2$ space-time dimensions leading for $D=2$ to
exact results. In this last case we present the bosonization rules for fermion
currents, calculate current-current correlation functions and establish the
connection between the fermionic and bosonic distribution functions in a
generic, nonequilibrium situation.
