English

A construction of pseudo-reductive groups with non-reduced root system

Group Theory 2024-01-09 v2

Abstract

We describe a straightforward construction of the pseudo-split absolutely pseudo-simple groups of minimal type with irreducible root systems of type BCnBC_n; these exist only in characteristic 22. We also give a formula for the dimensions of their irreducible modules.

Keywords

Cite

@article{arxiv.2205.00800,
  title  = {A construction of pseudo-reductive groups with non-reduced root system},
  author = {Michael Bate and Gerhard Röhrle and Damian Sercombe and David I. Stewart},
  journal= {arXiv preprint arXiv:2205.00800},
  year   = {2024}
}

Comments

22 pages; version accepted for publication in Transformation Groups; appendix added to show an alternative approach using a significant theorem in Conrad--Gabber--Prasad

R2 v1 2026-06-24T11:04:34.212Z