Effective string theory

Abstract
The effective conformal field theory governing the long-distance dynamics of string solitions in four dimensions, such as the Nielsen-Olesen vortex or QCD strings, is described. It is an interacting Poincaré-invariant conformal field theory with four bosons and c=26. The compatibility of these naively contradictory features is explicitly demonstrated through second order in a perturbation expansion about the long-string vacuum.