  We study a fluctuation current through a superconducting ring placed in a
space with the Kerr metric. This attempt aims at exploring conceptual problem;
namely, we are concerned with the question about the condensed state in an
extreme space-time. The superconducting ring is supposed to be placed in the
space surrounding the Kerr black hole (KBH) such that the rotating axis of the
KBH penetrates the center of the ring. The formulation is based on the
Landau-Ginzburg free energy functional of linear form. The resultant
fluctuation current shows several peculiar features that reflect characteristic
aspects of the KBH; that is, the effect of the Kerr metric gives rise to the
shift of superconducting transition temperature as well as the scale change of
absolute temperature.
