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arXiv 2203.01210math.GR
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直角建筑中格子的可公度性

Commensurability of lattices in right-angled buildings

Sam Shepherd

AI总结:

本文证明均匀格子与图积弱可公度等价于其凸子群可分离,并推论特殊立方复形有共同有限覆盖,还推广至Coxeter群、Artin群及Fuchsian建筑的拟等距刚性。

摘要:

设$Γ$为有限群的图积,其底层图为有限图,并设$Δ$为相关的直角建筑。我们证明,在立方体自同构群Aut$(Δ)$中,一个均匀格子$Λ$与$Γ$弱可公度,当且仅当$Λ$的所有凸子群都是可分离的。作为推论,任何两个以$Δ$为万有覆盖的有限特殊立方复形都有一个共同的有限覆盖。我们定理的一个重要特例是$Γ$为直角Coxeter群且$Δ$为相关的Davis复形。我们还获得了直角Artin群的类似结果。此外,当$Δ$具有Fuchsian建筑结构时,我们推导出群$Γ$的拟等距刚性。

英文摘要:

Let $Γ$ be a graph product of finite groups, with finite underlying graph, and let $Δ$ be the associated right-angled building. We prove that a uniform lattice $Λ$ in the cubical automorphism group Aut$(Δ)$ is weakly commensurable to $Γ$ if and only if all convex subgroups of $Λ$ are separable. As a corollary, any two finite special cube complexes with universal cover $Δ$ have a common finite cover. An important special case of our theorem is where $Γ$ is a right-angled Coxeter group and $Δ$ is the associated Davis complex. We also obtain an analogous result for right-angled Artin groups. In addition, we deduce quasi-isometric rigidity for the group $Γ$ when $Δ$ has the structure of a Fuchsian building.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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