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arXiv · 1509.02449

Maximality of hyperspecial compact subgroups avoiding Bruhat-Tits theory

Marco Maculan
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Abstract

Let $k$ be a complete non-archimedean field (non trivially valued). Given a reductive $k$-group $G$, we prove that hyperspecial subgroups of $G(k)$ (i.e. those arising from reductive models of $G$) are maximal among bounded subgroups. The originality resides in the argument: it is inspired by the case of $\textrm{GL}_n$ and avoids all considerations on the Bruhat-Tits building of $G$.

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Marco Maculan. 2015-09-08. Maximality of hyperspecial compact subgroups avoiding Bruhat-Tits theory. https://arxiv.org/abs/1509.02449

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