Symplectic Resolutions for Nilpotent Orbits
  We prove that any symplectic resolution of the closure of a nilpotent orbit in a semi-simple complex Lie algebra is isomorphic to the collapsing of the cotangent bundle of a projective homogenous variety. Then we give a complete characterization of those nilpotent orbits whose closure admit a symplectic resolution. 
Baohua Fu