Topology of Strongly Correlated Systems
TOPOLOGICAL EXCITATIONS AND SECOND ORDER TRANSITIONS IN 3D O(N) MODELS
Luís M. A. Bettencourt
Abstract
I discuss several examples of critical phenomena in O(N) models where topological excitations play an important role at criticality. I focus particular attention on the O(2) model in 3D, where recent measurements of the vortex string length distribution in equilibrium suggest the existence of a quantitative picture of the critical behavior in terms of defects. The compatibility of this perspective with renormalization group predictions is examined.