DU-BOIS INVARIANTS OF ISOLATED COMPLETE INTERSECTION SINGULARITIES

We define Du Bois invariants for isolated singularities of complex spa ces. We relate them to the Hedge numbers of the local and vanishing co homology groups. Our main results express the Tjurina number of certai n Gorenstein singularities in terms of Du Bois invariants and Hedge nu mbers of the link, and express the Hedge numbers of the Milnor fibre o f certain three-dimensional complete intersections in similar terms. W e also address the question of the semicontinuity of the Du Bois invar iants under deformation of the singularity.