Decomposition numbers for the principal $\Phi_{2n}$-block of $\mathrm{Sp}_{4n}(q)$ and $\mathrm{SO}_{4n+1}(q)$

Olivier Dudas; Emily Norton

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arXiv · 2102.06055

Decomposition numbers for the principal $\Phi_{2n}$-block of $\mathrm{Sp}_{4n}(q)$ and $\mathrm{SO}_{4n+1}(q)$

Olivier Dudas·Emily Norton

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Abstract

We compute the decomposition numbers of the unipotent characters lying in the principal $\ell$-block of a finite group of Lie type $B_{2n}(q)$ or $C_{2n}(q)$ when $q$ is an odd prime power and $\ell$ is an odd prime number such that the order of $q$ mod $\ell$ is $2n$. Along the way, we extend to these finite groups the results of \cite{DVV19} on the branching graph for Harish-Chandra induction and restriction.

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BibTeX RIS

Olivier Dudas, Emily Norton. 2021-02-11. Decomposition numbers for the principal $\Phi_{2n}$-block of $\mathrm{Sp}_{4n}(q)$ and $\mathrm{SO}_{4n+1}(q)$. https://arxiv.org/abs/2102.06055

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