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Quasi-isolated elements in reductive groups

Cédric Bonnafé
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Abstract

A semisimple element $s$ of a connected reductive group $G$ is said {\it quasi-isolated} (respectively {\it isolated}) if $C_G(s)$ (respectively $C_G^0(s)$) is not contained in a Levi subgroup of a proper parabolic subgroup of $G$. We study properties of quasi-isolated semisimple elements and give a classification in terms of the affine Dynkin diagram of $G$. Tables are provided for adjoint simple groups.

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Cédric Bonnafé. 2004-02-17. Quasi-isolated elements in reductive groups. https://arxiv.org/abs/math/0402276

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