Hyperbolic groups that are not commensurably co-hopfian

Sela proved that every torsion-free one-ended hyperbolic group is co-Hopfian. We prove that there exist torsion-free one-ended hyperbolic groups that are not commensurably co-Hopfian. In particular, we show that the fundamental group of every simple surface amalgam is not commensurably co-Hopfian.

Bibliografiska uppgifter
Huvudupphovsmän: Stark, E, Woodhouse, DJ
Materialtyp: Journal article
Språk:English
Publicerad: Oxford University Press 2020
Beskrivning
Sammanfattning:Sela proved that every torsion-free one-ended hyperbolic group is co-Hopfian. We prove that there exist torsion-free one-ended hyperbolic groups that are not commensurably co-Hopfian. In particular, we show that the fundamental group of every simple surface amalgam is not commensurably co-Hopfian.