The values of unipotent characters at unipotent elements for groups of type $E_8$ and ${^2\!E}_6$

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteur principal: Hetz, Jonas
Format: Preprint
Publié: 2023
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866916148124057600
author Hetz, Jonas
author_facet Hetz, Jonas
contents In order to tackle the problem of generically determining the character tables of the finite groups of Lie type $\mathbf{G}(q)$ associated to a connected reductive group $\mathbf{G}$ over $\overline{\mathbb F}_p$, Lusztig developed the theory of character sheaves in the 1980s. The subsequent work of Lusztig and Shoji in principle reduces this problem to specifying certain roots of unity. The situation is particularly well understood as far as character values at unipotent elements are concerned. We complete the computation of the values of unipotent characters at unipotent elements for the groups $\mathbf{G}(q)$ where $\mathbf{G}$ is the simple group of type $E_8$, by specifying the aforementioned roots of unity for all prime powers $q$. We also resolve this task for the groups ${^2\!E}_6(q)$ when $q$ is a power of $p=2$. Our results thus conclude the project of computing the values of unipotent characters at unipotent elements for the simple exceptional groups of Lie type.
format Preprint
id arxiv_https___arxiv_org_abs_2309_09915
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle The values of unipotent characters at unipotent elements for groups of type $E_8$ and ${^2\!E}_6$
Hetz, Jonas
Representation Theory
Primary 20C33, Secondary 20G40, 20G41
In order to tackle the problem of generically determining the character tables of the finite groups of Lie type $\mathbf{G}(q)$ associated to a connected reductive group $\mathbf{G}$ over $\overline{\mathbb F}_p$, Lusztig developed the theory of character sheaves in the 1980s. The subsequent work of Lusztig and Shoji in principle reduces this problem to specifying certain roots of unity. The situation is particularly well understood as far as character values at unipotent elements are concerned. We complete the computation of the values of unipotent characters at unipotent elements for the groups $\mathbf{G}(q)$ where $\mathbf{G}$ is the simple group of type $E_8$, by specifying the aforementioned roots of unity for all prime powers $q$. We also resolve this task for the groups ${^2\!E}_6(q)$ when $q$ is a power of $p=2$. Our results thus conclude the project of computing the values of unipotent characters at unipotent elements for the simple exceptional groups of Lie type.
title The values of unipotent characters at unipotent elements for groups of type $E_8$ and ${^2\!E}_6$
topic Representation Theory
Primary 20C33, Secondary 20G40, 20G41
url https://arxiv.org/abs/2309.09915