Global monopoles in dilaton gravity

We analyse the gravitational field of a global monopole within the context of low energy string gravity, allowing for an arbitrary coupling of the monopole fields to the dilaton. Both massive and massless dilatons are considered. We find that, for a massless dilaton, the spacetime is generically singular, whereas when the dilaton is massive, the monopole generically induces a long range dilaton cloud. We compare and contrast these results with the literature. PACS numbers: 04.70.-b, 11.27.+d, 98.80.Cq gr-qc/9709029 Typeset using REVT E X I. INTRODUCTION Cosmologists have been attracted to topological defects as a possible source for the density perturbations which seeded galaxy formation 1. Phase transitions in the early universe can give rise to various types of defect. Briefly, a defect is a discontinuity in the vacuum, and can be classified according to the topology of the vacuum manifold of the field theory model being used. Disconnected vacuum manifolds give domain walls, non...