English

Extensions of multicurve stabilizers are hierarchically hyperbolic

Geometric Topology 2025-10-01 v2 Group Theory

Abstract

For a closed and orientable surface of genus at least 2, we prove the surface group extensions of the stabilizers of multicurves are hierarchically hyperbolic groups. This answers a question of Durham, Dowdall, Leininger, and Sisto. We also include an appendix that employs work of Charney, Cordes, and Sisto to characterize the Morse boundaries of hierarchically hyperbolic groups whose largest acylindrical action on a hyperbolic space is on a quasi-tree.

Keywords

Cite

@article{arxiv.2107.14116,
  title  = {Extensions of multicurve stabilizers are hierarchically hyperbolic},
  author = {Jacob Russell},
  journal= {arXiv preprint arXiv:2107.14116},
  year   = {2025}
}

Comments

Version accepted to Geometry & Topology

R2 v1 2026-06-24T04:39:25.420Z