Ginzburg-Landau Theory of the Electroweak Phase Transition and   Analytical Results
  The phase transition of the electroweak vacuum induced by a strong magnetic field is examined, and a connection is made with the Ginzburg-Landau theory of type-II superconductivity. For solutions of the exact nonlinear field equations of the electroweak theory with lattice periodicity in directions perpendicular to the magnetic field, it is proven that, likewise, each lattice cell must enclose an integer number of quanta of magnetic flux. Close to the lower critical magnetic field, a perturbative method developed by MacDowell and the author is used to study properties of the lattice solutions. Analytical expressions for observables are obtained in terms of a complex parameter $\tau$ specifying the lattice and it is shown that the triangular Abrikosov solution constitutes a local minimum of the energy provided $M_H > M_Z$.   PACS numbers: 11.15.Kc, 11.15.Ex, 74.60.-w, 05.70.Fh 
Ola Tornkvist