Uniqueness of Crepant Resolutions and Symplectic Singularities


We prove the uniqueness of crepant resolutions for some quotient singularities and for some nilpotent orbits. The finiteness of nonisomorphic symplectic resolutions for 4-dimensional symplectic singularities is proved. We also give an example of symplectic singularity which admits two non-equivalent symplectic resolutions.