English

Relative Untwisted Outer Space for Right-Angled Artin Groups

Group Theory 2025-03-13 v1 Geometric Topology

Abstract

For G, H two finite collections of finitely generated subgroups of a right-angled Artin group A, the untwisted McCool group U(A; G, Ht) is the subgroup of untwisted outer automorphisms of A preserving the conjugacy class of each element of G and acting trivially up to conjugacy on each element of H. We prove that when the elements of G are standard subgroups of A, U(A; G, Ht) acts properly cocompactly on a finite-dimensional subcomplex of the spine of untwisted outer space for A, providing a geometric model for this group and proof that it is of type VF.

Keywords

Cite

@article{arxiv.2503.09588,
  title  = {Relative Untwisted Outer Space for Right-Angled Artin Groups},
  author = {Adrien Abgrall},
  journal= {arXiv preprint arXiv:2503.09588},
  year   = {2025}
}

Comments

39 pages

R2 v1 2026-06-28T22:17:53.488Z