English

KW-sections for exceptional type Vinberg's $\theta$-groups

Rings and Algebras 2010-05-12 v2 Group Theory

Abstract

Let kk be an algebraically closed field of characteristic not equal to 2 or 3, let GG be an almost simple algebraic group of type F4F_4, G2G_2 or D4D_4 and let θ\theta be an automorphism of GG of finite order, coprime to the characteristic. In this paper we consider the θ\theta-group (in the sense of Vinberg) associated to these choices; we classify the positive rank automorphisms and give their Kac diagrams and we describe the little Weyl group in each case. As a result we show that all such θ\theta-groups have KW-sections, confirming a conjecture of Popov in these cases.

Keywords

Cite

@article{arxiv.0805.2064,
  title  = {KW-sections for exceptional type Vinberg's $\theta$-groups},
  author = {Paul Levy},
  journal= {arXiv preprint arXiv:0805.2064},
  year   = {2010}
}

Comments

Fairly substantially revised, correction to table 2 (including the automorphism with diagram 01001) and to the relevant sections of the text. 25 pages, 3 tables.

R2 v1 2026-06-21T10:40:24.634Z