Publication at Faculty of Mathematics and Physics |
2011
Abstract
Using principles of the Fadeev-Lovelace-Watson multiple scattering expansion, a T-matrix approximation is derived which coincides with the Galitskii-Feynman T matrix in the normal state and yields the gap in the superconducting state. Unlike other T-matrix approaches, the theory satisfies not only the self-consistent Thouless criterion but also the Baym-Kadanoff conditions for a conserving theory in equilibrium.
In single-mode approximation it simplifies to the Eliashberg theory.