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arXiv · 2402.09960

Rationality of extended unipotent characters

Olivier Dudas·Gunter Malle
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Abstract

We determine the rationality properties of unipotent characters of finite reductive groups arising as fixed points of disconnected reductive groups under a Frobenius map. In the proof we use realisations of characters in $\ell$-adic cohomology groups of Deligne--Lusztig varieties as well as block theoretic considerations.

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Olivier Dudas, Gunter Malle. 2024-02-15. Rationality of extended unipotent characters. https://arxiv.org/abs/2402.09960

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