Quantum dot experiments show new aspects of electron correlation physics
that are inaccessible in bulk materials. One example is the transport
through Kondo dots for large voltage bias, i.e. beyond the linear response
regime.
The competition between strong-coupling Kondo physics and decoherence
induced by the nonequilibrium current determines the behavior in this
regime. Such quantum many-body problems far away from equilibrium are
theoretically not well understood and I present an overview of some
new results obtained using the flow equation method.