O(D,D) SYMMETRY IN QUANTUM COSMOLOGY

We analyze the quantum cosmology of one-loop string effective models w hich exhibit an O(d,d) symmetry. It is shown that due to the large sym metry of these models the Wheeler-de Witt equation can completely be s olved. As a result, we find a basis of solutions with well-defined tra nsformation properties under O(d,d) and under scale factor duality in particular. The general results are explicitly applied to 2-dimensiona l target spaces while some aspects of higher dimensional cases are als o discussed. Moreover, a semiclassical wave function for the 2-dimensi onal black hole is constructed as a superposition of our basis.