English

Almost cyclic regular elements in irreducible representations of simple algebraic groups

Representation Theory 2022-03-08 v1 Group Theory

Abstract

Let GG be a simple linear algebraic group defined over an algebraically closed field of characteristic p0p\geq 0 and let ϕ\phi be a pp-restricted irreducible representation of GG. Let TT be a maximal torus of GG and sTs\in T. We say that ss is strongly regular if α(s)β(s)\alpha(s)\ne\beta(s) for all distinct TT-roots α\alpha and β\beta of GG. Our main result states that if all but one of the eigenvalues of ϕ(s)\phi(s) are of multiplicity 1 then, with a few specified exceptions, ss is strongly regular. This can be viewed as an extension of our earlier result saying that under the same hypotheses, ss must be regular and all non-zero weights of ϕ\phi are of multiplicity 1.

Keywords

Cite

@article{arxiv.2203.02900,
  title  = {Almost cyclic regular elements in irreducible representations of simple algebraic groups},
  author = {Donna M. Testerman and Alexandre Zalesski},
  journal= {arXiv preprint arXiv:2203.02900},
  year   = {2022}
}
R2 v1 2026-06-24T10:03:31.463Z