  A theory of the Kondo effect in quantum dots at zero temperature in the
presence of arbitrary intense AC potentials is presented.We generalize the
Friedel-Langreth sum rule to take care of charge conservation and propose a
consistent procedure to study a time dependent Anderson Hamiltonian. The effect
of the AC potential on both the quantum dot density of states and the linear
conductance shows the importance of using a theory which describes intradot
finite interaction and nonperturbative effects.
