2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/78921Let G be a finite group of automorphisms of a nonsingular complex threefold M such that the canonical bundle omega_M is locally trivial as a G-sheaf. We prove that the Hilbert scheme Y=GHilb M parametrising G-clusters in M is a crepant resolution of X=M/G and that there is a derived equivalence (Fourier- Mukai transform) between coherent sheaves on Y and coherent G-sheaves on M. This identifies the K theory of Y with the equivariant K theory of M, and thus generalises the classical McKay correspondence. Some higher dimensional extensions are possible.Dedicated to Andrei Tyurin's 60th birthday. This draft is completely rewritten; it contains in particular a complete proof of Nakamura's conjecture that the Hilbert scheme of G-clusters is a crepant resolution for G in SL(3,C). 27 pp. submitted to J. Amer. Math. SocAlgebraic Geometrytext