Critical points of infinite order in charge-density-wave systems and in superconductors

Two models, one describing charge-density-wave formation and the other (the Ginzburg-Landau model) describing the superconducting state, are studied and shown to exhibit infinite-order critical points. Related models exhibiting a Lifshitz point, a bicritical point, and a tetracritical point are also discussed. © 1981 The American Physical Society.