English

Birational geometry of symplectic resolutions of nilpotent orbits II

Algebraic Geometry 2007-05-23 v2

Abstract

In this paper we shall study symplectic resolutions of a nilpotent orbit closure of a complex simple Lie algebra \g. We shall introduce an equivalence relation in the set of parabolic subgroups of GG in terms of marked Dynkin diagrams. We start with a nilpotent orbit closure which admits a Springer resolution with a parabolic subgroup P0P_0 of GG. Then we prove that all symplectic resolution of the nilpotent closure are Springer resolutions with PP which are equivalent to P0P_0. Here all symplectic resolutions are connected by Mukai flops. We need three types of Mukai flops (types A, D and E_6) in connecting symplectic resolutions. In particular, Mukai flops of type E_6 are new. All arguments of Part I : math.AG/0404072 which use flags, are replaced by those which use only Dynkin diagrams.

Keywords

Cite

@article{arxiv.math/0408274,
  title  = {Birational geometry of symplectic resolutions of nilpotent orbits II},
  author = {Yoshinori Namikawa},
  journal= {arXiv preprint arXiv:math/0408274},
  year   = {2007}
}

Comments

Main results hold for arbitrary simple Lie algebras, that is, the conjectual part in the previous version is established