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.

Bibliográfalaš dieđut
Váldodahkkit: Stark, E, Woodhouse, DJ
Materiálatiipa: Journal article
Giella:English
Almmustuhtton: Oxford University Press 2020
Govvádus
Čoahkkáigeassu: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.