English

Non-residually finite groups hyperbolic relative to residually finite subgroups

Group Theory 2019-03-07 v2

Abstract

Let mm and kk be integers such that m,k>1|m|, \, |k| >1 and gcd(m,k)=1\gcd (m,k)=1. We show that all Baumslag-Solitar groups BS(m,mk)BS(m,mk) are non-residually finite groups hyperbolic relative to residually finite subgroups. By a result of Osin (2007), this implies that there exists a non-residually finite hyperbolic group, thus solving a long-standing open problem of Gromov (1987). We also show that all BS(m,mk)BS(m, mk) are non-Hopfian groups hyperbolic relative to Hopfian subgroups.

Keywords

Cite

@article{arxiv.1903.00838,
  title  = {Non-residually finite groups hyperbolic relative to residually finite subgroups},
  author = {Jan Kim and Donghi Lee},
  journal= {arXiv preprint arXiv:1903.00838},
  year   = {2019}
}

Comments

Due to an important error in Section 4, we would like to politely ask to withdraw this manuscript. We greatly appreciate Professors Yves Cornulier, Francois Dahmani, Anthony Genevois, Daniel Groves, Ilya Kapovich, Dennis Osin and Henry Wilton for their kind comments and pointing out the error

R2 v1 2026-06-23T07:56:34.492Z