Discrete two-generator subgroups of ${\rm PSL_2}$ over non-archimedean local fields

التفاصيل البيبلوغرافية
العنوان: Discrete two-generator subgroups of ${\rm PSL_2}$ over non-archimedean local fields
المؤلفون: Conder, Matthew J., Schillewaert, Jeroen
سنة النشر: 2022
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Group Theory, Mathematics - Geometric Topology, 20E08, 22E40
الوصف: Let $K$ be a non-archimedean local field with residue field of characteristic $p$. We give necessary and sufficient conditions for a two-generator subgroup $G$ of ${\rm PSL_2}(K)$ to be discrete, where either $K=\mathbb{Q}_p$ or $G$ contains no elements of order $p$. We give a practical algorithm to decide whether such a subgroup $G$ is discrete. We also give practical algorithms to decide whether a two-generator subgroup of either ${\rm SL_2}(\mathbb{R})$ or ${\rm SL_2}(K)$ (where $K$ is a finite extension of $\mathbb{Q}_p$) is dense. A crucial ingredient for this work is a structure theorem for two-generator groups acting by isometries on a $\Lambda$-tree.
Comment: 19 pages, 5 figures, 1 table. Version 2 has some minor updates
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2208.12404
رقم الأكسشن: edsarx.2208.12404
قاعدة البيانات: arXiv