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Bibliographic Details
Main Authors: Stewart, David I., Thomas, Adam R.
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2401.07303
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author Stewart, David I.
Thomas, Adam R.
author_facet Stewart, David I.
Thomas, Adam R.
contents Let G be a simple algebraic group over an algebraically closed field k of characteristic 2. We consider analogues of the Jacobson-Morozov theorem in this setting. More precisely, we classify those nilpotent elements with a simple 3-dimensional Lie overalgebra in $\mathfrak{g} := \text{Lie}(G)$ and also those with overalgebras isomorphic to the algebras $\text{Lie}(\text{SL}_2)$ and $\text{Lie}(\text{PGL}_2)$. This leads us to calculate the dimension of Lie automiser $\mathfrak{n}_\mathfrak{g}(k\cdot e)/\mathfrak{c}_\mathfrak{g}(e)$ for all nilpotent orbits; in even characteristic this quantity is very sensitive to isogeny.
format Preprint
id arxiv_https___arxiv_org_abs_2401_07303
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On extensions of the Jacobson-Morozov theorem to even characteristic
Stewart, David I.
Thomas, Adam R.
Representation Theory
Group Theory
Rings and Algebras
17B45
Let G be a simple algebraic group over an algebraically closed field k of characteristic 2. We consider analogues of the Jacobson-Morozov theorem in this setting. More precisely, we classify those nilpotent elements with a simple 3-dimensional Lie overalgebra in $\mathfrak{g} := \text{Lie}(G)$ and also those with overalgebras isomorphic to the algebras $\text{Lie}(\text{SL}_2)$ and $\text{Lie}(\text{PGL}_2)$. This leads us to calculate the dimension of Lie automiser $\mathfrak{n}_\mathfrak{g}(k\cdot e)/\mathfrak{c}_\mathfrak{g}(e)$ for all nilpotent orbits; in even characteristic this quantity is very sensitive to isogeny.
title On extensions of the Jacobson-Morozov theorem to even characteristic
topic Representation Theory
Group Theory
Rings and Algebras
17B45
url https://arxiv.org/abs/2401.07303