Time-periodic solutions of the time-dependent Ginzburg-Landau equations of superconductivity

The problem of existence of time-periodic solutions forthe time-dependent Ginzburg-Landau equations of superconductivityis discussed. It is assumed that the applied magnetic field His -periodic in time, and so is the associated dynamicalprocess. We prove the existence of -periodic solutions intime, which are exactly the fixed points of the associated periodmapping.