On computing the spherical roots for a class of spherical subgroups

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Avdeev, Roman
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917391839002624
author Avdeev, Roman
author_facet Avdeev, Roman
contents Given a connected reductive algebraic group $G$, we consider the class of spherical subgroups $H \subset G$ such that $H$ is regularly embedded in a parabolic subgroup $P \subset G$ and $H,P$ have a common Levi subgroup $L$. In a previous paper, the author developed a fast algorithm that reduces the computation of the set of spherical roots for such subgroups $H$ to the case where the quotient of Lie algebras $\operatorname{Lie} P / \operatorname{Lie} H$ is a strictly indecomposable spherical $L$-module. In this paper, we complete the classification of all such cases and compute the spherical roots for each of them, which enables one to use the above fast algorithm directly for computing the spherical roots for arbitrary spherical subgroups in the class under consideration.
format Preprint
id arxiv_https___arxiv_org_abs_2604_07056
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle On computing the spherical roots for a class of spherical subgroups
Avdeev, Roman
Algebraic Geometry
Group Theory
14M27, 14M17, 20G07
Given a connected reductive algebraic group $G$, we consider the class of spherical subgroups $H \subset G$ such that $H$ is regularly embedded in a parabolic subgroup $P \subset G$ and $H,P$ have a common Levi subgroup $L$. In a previous paper, the author developed a fast algorithm that reduces the computation of the set of spherical roots for such subgroups $H$ to the case where the quotient of Lie algebras $\operatorname{Lie} P / \operatorname{Lie} H$ is a strictly indecomposable spherical $L$-module. In this paper, we complete the classification of all such cases and compute the spherical roots for each of them, which enables one to use the above fast algorithm directly for computing the spherical roots for arbitrary spherical subgroups in the class under consideration.
title On computing the spherical roots for a class of spherical subgroups
topic Algebraic Geometry
Group Theory
14M27, 14M17, 20G07
url https://arxiv.org/abs/2604.07056