Anomalous Electrical Conductivity above the Superconducting Transition

The rise in the electrical conductivity as a material approaches its superconducting transition is described in terms of fluctuation theory. About $T_c$ small regions become superconducting and can carry an anomalous current, thereby causing a rise in conductivity. The use of the Kubo formula permits the estimation of the contribution from this source. A comparison of this estimate with previous theories and experiment is carried out.