  A one-dimensional system of interacting electrons out of equilibrium is
studied in the framework of the Luttinger liquid model. We analyze several
setups and develop a theory of tunneling into such systems. A remarkable
property of the problem is the absence of relaxation in energy distribution
functions of left- and right-movers, yet the presence of the finite dephasing
rate due to electron-electron scattering, which smears zero-bias-anomaly
singularities in the tunneling density of states.
