Generic stabilizers in actions of simple algebraic groups
Group Theory
2025-05-27 v5 Algebraic Geometry
Abstract
In this paper we treat faithful actions of simple algebraic groups on irreducible modules and on the associated Grassmannian varieties. By explicit calculation, we show that in each case, with essentially one exception (only in characteristic 2), there is a dense open subset any point of which has stabilizer conjugate to a fixed subgroup, called the generic stabilizer. We provide tables listing generic stabilizers in the cases where they are non-trivial; in addition we decide whether or not there is a dense orbit, or a regular orbit for the action on the module.
Cite
@article{arxiv.1904.13375,
title = {Generic stabilizers in actions of simple algebraic groups},
author = {R. M. Guralnick and R. Lawther},
journal= {arXiv preprint arXiv:1904.13375},
year = {2025}
}
Comments
This version corrects a result about the existence of regular orbits; there were a few very small cases where there is a regular orbit which was not noted in the original version