Topological models of non-critical strings

Abstract

I describe the non-critical c = 1 string theory in the continuum, from the point of view of topological symmetry. The c = 1 string is first discussed in the Liouville formulation, then the topological invariance of non-critical strings is demonstrated, and finally a manifestly topological coset model of compactified c = 1 string theory is presented. It is shown that this model reproduces correlation functions of this string theory in the continuum directly at nonzero cosmological constant, without recourse to perturbation theory in the cosmological constant and analytic continuation procedures. The model also gives directly the partition function of the compactified theory at the self-dual radius.