For relatively hyperbolic groups, we investigate conditions guaranteeing that the subgroup generated by two relatively quasiconvex subgroups Q 1 and Q 2 is relatively quasiconvex and isomorphic to Q 1* Q 1∩Q2 Q 2. The main theorem extends results for quasiconvex subgroups of word-hyperbolic groups, and results for discrete subgroups of isometries of hyperbolic spaces. An application on separability of double cosets of quasiconvex subgroups is included.
ASJC Scopus subject areas
- Geometry and Topology