Height in splittings of hyperbolic groups

Abstract

Suppose $H$ is a hyperbolic subgroup of a hyperbolic group $G$. Assume there exists $n>0$ such that the intersection of $n$ essentially distinct conjugates of $H$ is always finite. Further assume $G$ splits over $H$ with hyperbolic vertex and edge groups and the two inclusions of $H$ are quasi-isometric embeddings. Then $H$ is quasiconvex in $G$. This answers a question of Swarup and provides a partial converse to the main theorem of \cite{GMRS}.

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