Fixed points of nonlinear sigma models in d>2

AbstractUsing Wilsonian methods, we study the renormalization group flow of the nonlinear sigma model in any dimension d, restricting our attention to terms with two derivatives. At one loop we always find a Ricci-type flow. When symmetries completely fix the internal metric, we compute the beta function of the single remaining coupling, without any further approximation. For d>2 and positive curvature, there is a nontrivial fixed point, which could be used to define an ultraviolet limit, in spite of the perturbative nonrenormalizability of the theory. Potential applications are briefly mentioned