  The superconductive phase transition in the Ginzburg-Landau theory (or
Coulomb-Higgs phase transition of scalar QED in 3D) is discussed in a dual
formulation which focuses on the magnetic rather than the electric excitations
of the system. Renormalization group analysis of the dual formulation reveals
the transition to be of second order and of a new universality class. Whereas
coherence length and specific heat have XY-model exponents, the magnetic
penetration depth shows mean-field behavior. Experimental evidence for these
predictions is discussed.
