DEFORMATIONS OF HYPERCOMPLEX STRUCTURES

Twister theory shows that deformations of a hypercomplex manifold corr espond to deformations of a canonically constructed holomorphic map fr om the twister space of the hypercomplex manifold onto the complex pro jective line. Applying Horikawa's theory of deformations of maps, eve calculate deformations of compact quotients and twists of the associat ed bundles of quaternionic manifolds. In particular, deformations of h ypercomplex structures on Stiefel manifolds are discussed.