English

Relatively Hyperbolic Groups have Semistabile Fundamental Group at Infinity

Group Theory 2020-12-16 v2

Abstract

Suppose GG is a 1-ended finitely generated group that is hyperbolic relative to P a finite collection of 1-ended finitely generated subgroups. Our main theorem states that if the boundary (G,P)\partial (G, P) has no cut point, then GG has semistable fundamental group at \infty. Under mild conditions on GG and the members of P the 1-ended hypotheses and the no cut point condition can be eliminated to obtain the same semistability conclusion. We give an example that shows our main result is somewhat optimal. Finally, we improve a "double dagge" result of F. Dahmani and D. Groves.

Keywords

Cite

@article{arxiv.1709.02420,
  title  = {Relatively Hyperbolic Groups have Semistabile Fundamental Group at Infinity},
  author = {Michael L. Mihalik and Eric Swenson},
  journal= {arXiv preprint arXiv:1709.02420},
  year   = {2020}
}

Comments

27 pages 3 figures

R2 v1 2026-06-22T21:36:28.834Z