The residual finiteness of negatively curved polygons of finite groups

• 成果类型: Article
• 署名作者: Wise, DT
• 署名单位: University of California System; University of California Berkeley
• 刊物名称: INVENTIONES MATHEMATICAE
• ISSN/ISSBN: 0020-9910
• DOI: 10.1007/s002220200224
• 发表日期: 2002
• 页码: 579-617
• 关键词: hyperbolic groups

摘要

A subgroup M subset of G is almost malnormal provided that for each g epsilon G - M, the intersection M-g boolean AND M is finite. It is proven that the free product of two virtually free groups amalgamating a finitely generated almost malnormal subgroup, is residually finite. A consequence of a generalization of this result is that an acute-angled n-gon of finite groups is residually finite if n greater than or equal to 4. Another consequence is that if G acts properly discontinuously and cocompactly on a 2-dimensional hyperbolic building whose chambers have acute angles and at least 4 sides, then G is residually finite.