English

Universal virtual braid groups

Group Theory 2026-04-10 v2 Geometric Topology

Abstract

We introduce the universal virtual braid group UVn(c)UV_n(c), which provides a unified algebraic framework for virtual braid--type structures with cc types of crossings and admits natural quotient maps onto the standard families in the literature. We prove that UVn(c)UV_n(c) contains a right-angled Artin subgroup of finite index, yielding strong structural consequences: residual finiteness, linearity, solvability of the word and conjugacy problems, and the Tits alternative. For n5n\ge 5, the commutator subgroup UVn(c)UV_n(c)' is perfect, and every non-abelian finite image contains a subgroup isomorphic to the symmetric group SnS_n; in particular, SnS_n is the smallest non-abelian finite quotient. These rigidity phenomena persist under a broad class of natural quotients, including virtual braid, virtual singular braid, virtual twin and multi-virtual braid groups. We further obtain a complete classification of subgroup separability (LERF) and the Howson property for UVn(c)UV_n(c) and its pure subgroup PUVn(c)PUV_n(c), showing that both properties hold precisely for n3n\le 3. We also compute the virtual cohomological dimension, determine the center, prove that the finite-index RAAG subgroup is characteristic, and construct explicit finite quotients of UVn(c)UV_n(c) whose order is strictly larger than n!n!.

Keywords

Cite

@article{arxiv.2604.01633,
  title  = {Universal virtual braid groups},
  author = {Oscar Ocampo},
  journal= {arXiv preprint arXiv:2604.01633},
  year   = {2026}
}

Comments

20 pages. Corollary 3.7 removed from the first version; subsequent remark renumbered. Comments are welcome