English

On the affinization of a nilpotent orbit cover

Representation Theory 2024-11-21 v2

Abstract

Let g\mathfrak{g} be a simple classical Lie algebra over C\mathbb{C} and GG be the adjoint group. Consider a nilpotent element ege\in \mathfrak{g}, and the adjoint orbit O=Ge\mathbb{O}=Ge. The formal slices to the codimension 22 orbits in the closure Og\overline{\mathbb{O}}\subset \mathfrak{g} are well-known due to the work of Kraft and Procesi. In this paper, we prove a similar result for the universal GG-equivariant cover O~\widetilde{\mathbb{O}} of O\mathbb{O}. Namely, we describe the codimension 22 singularities for its affinization Spec(C[O~])Spec(\mathbb{C}[\widetilde{\mathbb{O}}]).

Keywords

Cite

@article{arxiv.2003.09356,
  title  = {On the affinization of a nilpotent orbit cover},
  author = {Dmytro Matvieievskyi},
  journal= {arXiv preprint arXiv:2003.09356},
  year   = {2024}
}

Comments

I am grateful to Shilin Yu for pointing out a mistake in the first version of the paper. The second version includes description of symmetries acting on the codimension 2 singularities, and a discussion of expected symplectic duality, which this paper provides evidence to