Derivation of Ginzburg-Landau theory for a one-dimensional system with   contact interaction
  In a recent paper we give the first rigorous derivation of the celebrated Ginzburg-Landau (GL) theory, starting from the microscopic Bardeen-Cooper-Schrieffer (BCS) model. Here we present our results in the simplified case of a one-dimensional system of particles interacting via a delta-potential. 
Rupert L. Frank, Christian Hainzl, Robert Seiringer, Jan Philip   Solovej
math-ph cond-mat.supr-con math.MP