English

Automorphisms of contact graphs of ${\rm CAT(0)}$ cube complexes

Geometric Topology 2026-03-25 v2 Group Theory

Abstract

We show that, under weak assumptions, the automorphism group of a CAT(0){\rm CAT(0)} cube complex XX coincides with the automorphism group of Hagen's contact graph C(X)\mathcal{C}(X). The result holds, in particular, for universal covers of Salvetti complexes, where it provides an analogue of Ivanov's theorem on curve graphs of non-sporadic surfaces. This highlights a contrast between contact graphs and Kim-Koberda extension graphs, which have much larger automorphism group. We also study contact graphs associated to Davis complexes of right-angled Coxeter groups. We show that these contact graphs are less well-behaved and describe exactly when they have more automorphisms than the universal cover of the Davis complex.

Keywords

Cite

@article{arxiv.2001.08493,
  title  = {Automorphisms of contact graphs of ${\rm CAT(0)}$ cube complexes},
  author = {Elia Fioravanti},
  journal= {arXiv preprint arXiv:2001.08493},
  year   = {2026}
}

Comments

16 pages, no figures; v2: published version, open access on IMRN