Global Anomalies In String Theory

Global Anomalies in String Theory, in Proceedings from a Symposium on Anomalies, Geometry, Topology PDF) Abstract

Various questions involving global anomalies in particle theory and string theory are addressed. It is shown that the question of whether a manifold is a spin manifold is equivalent to a question about global anomalies in the propagation of a point particle. In the super-string case, it is shown that the measure of the heterotic theory has no global anomalies on any Riemann surface. This generalizes known one loop results. Also, a topological condition is derived which restricts the possible choices of Wilson lines for grand unified symmetry breaking. It is argued that the long-term development of global anomalies in string theory will involve eventual study of global anomalies in the determinant of the Dirac-Ramond operator.