GENERALIZED DUALITY AND SINGULAR STRINGS IN HIGHER DIMENSIONS

Deformations of gauged WZW actions are constructed for any pair (G, H) by taking different embeddings of the gauge group H subset-of G as it acts on the left and right of the group element g. This leads to models that are dual to each other, generalizing the axial/vector duality of the two-dimensional black hole manifold. The classical equations are completely solved for any pair (G, H) and in particular for the anti-de-Sitter string based on SO(d - 1,2)/SO(d - 1,1) for which the normal modes are determined. Duality is demonstrated for models that have the same set of normal modes. Concentrating on SO(2,2)/SO(2,1), the metric and dilaton fields of the d = 3 string as well as some of the dual generalizations are obtained. They have curvature singularities and represent new singular solutions of Einstein's general relativity in three dimensions.