H. Glöckner and G. A. Willis have recently shown [2] that locally pro-$p$ contraction groups are nilpotent. The proof hinges on a fixed point result [2, Theorem B]: if the local field $\mathbb{F}_{p}(\!(t)\!)$ acts on its $d$-th power $\mathbb{F}_{p}(\!(t)\!)^{d}$ additively, continuously, and in an appropriately equivariant manner, then the action has a non-zero fixed point. We provide a short proof of this theorem.
H. Glöckner et G. A. Willis ont récemment démontré [2] que les groupes de contraction localement pro-$p$ sont nilpotents. Leur démonstration repose sur un résultat de point fixe [2, Theorem B] : si le corps local $\mathbb{F}_{p}(\!(t)\!)$ agit sur sa $d$-ième puissance $\mathbb{F}_{p}(\!(t)\!)^{d}$ additivement, continûment et de manière convenablement équivariante, alors l’action a un point fixe non nul. Nous présentons une démonstration courte de ce théorème.
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Alonso Beaumont  1
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@article{CRMATH_2025__363_G3_267_0,
author = {Alonso Beaumont},
title = {On the nilpotency of locally pro-$p$ contraction groups},
journal = {Comptes Rendus. Math\'ematique},
pages = {267--270},
year = {2025},
publisher = {Acad\'emie des sciences, Paris},
volume = {363},
doi = {10.5802/crmath.728},
language = {en},
}
Alonso Beaumont. On the nilpotency of locally pro-$p$ contraction groups. Comptes Rendus. Mathématique, Volume 363 (2025), pp. 267-270. doi: 10.5802/crmath.728
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