Existence of global strings coupled to gravity

Abstract

We consider σ-model strings and U(1) global strings coupled to gravity and look for static solutions with whole cylinder symmetry. We prove that in both cases there are no regular spatially compact solutions. The U(1) global string admits no asymptotically well-behaved solutions, whereas cr model strings can be constructed under certain assumptions. Finally we present somesingular solutions and show that one of the corresponds to a physical global string.