English

Powers of Dehn twists generating right-angled Artin groups

Group Theory 2021-08-18 v1

Abstract

We give a bound for the exponents of powers of Dehn twists to generate a right-angled Artin group. Precisely, if F\mathcal{F} is a finite collection of pairwise distinct simple closed curves on a finite type surface and if NN denotes the maximum of the intersection numbers of all pairs of curves in F\mathcal{F}, then we prove that {TγnγF}\{T_\gamma^n \,\vert\, \gamma \in \mathcal{F} \} generates a right-angled Artin group for all nN2+N+3n \geq N^2 + N + 3. This extends a previous result of Koberda, who proved the existence of a bound possibly depending on the underlying hyperbolic structure of the surface. In the course of the proof, we obtain a universal bound depending only on the topological type of the surface in certain cases, which partially answers a question due to Koberda.

Keywords

Cite

@article{arxiv.1909.03394,
  title  = {Powers of Dehn twists generating right-angled Artin groups},
  author = {Donggyun Seo},
  journal= {arXiv preprint arXiv:1909.03394},
  year   = {2021}
}

Comments

16 pages, 8 figures