The Hesselink stratification of nullcones and base change

• 成果类型: Article
• 署名作者: Clarke, Matthew C.; Premet, Alexander
• 署名单位: University of Cambridge; University of Manchester
• 刊物名称: INVENTIONES MATHEMATICAE
• ISSN/ISSBN: 0020-9910
• DOI: 10.1007/s00222-012-0401-8
• 发表日期: 2013
• 页码: 631-669
• 关键词: nilpotent orbits; unipotent elements; lie-algebras; instability; VARIETIES

摘要

Let G be a connected reductive algebraic group over an algebraically closed field of characteristic pa parts per thousand yen0. We give a case-free proof of Lusztig's conjectures (Lusztig in Transform. Groups 10:449-487, 2005) on so-called unipotent pieces. This presents a uniform picture of the unipotent elements of G which can be viewed as an extension of the Dynkin-Kostant theory, but is valid without restriction on p. We also obtain analogous results for the adjoint action of G on its Lie algebra and the coadjoint action of G on .