For relatively hyperbolic groups, we investigate conditions guaranteeing that the subgroup generated by two relatively quasiconvex subgroups and is relatively quasiconvex and isomorphic to . 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.
"Virtual amalgamation of relatively quasiconvex subgroups." Algebr. Geom. Topol. 12 (4) 1993 - 2002, 2012. https://doi.org/10.2140/agt.2012.12.1993