vix.ing · top · new · best · stats · spec

Andrews-Curtis groups

2025/06/28 by Gilman, Robert H., Myasnikov, Alexei G.
#FOS: Mathematics #Group Theory (math.GR)

paper · doi:10.48550/arxiv.2506.23031

Abstract

For any group G and integer k≥ 2 the Andrews-Curtis transformations act as a permutation group, termed the Andrews-Curtis group ACk(G), on the subset Nk(G) ⊂ Gk of all k-tuples that generate G as a normal subgroup (provided Nk(G) is non-empty). The famous Andrews-Curtis Conjecture is that if G is free of rank k, then ACk(G) acts transitively on Nk(G). The set Nk(G) may have a rather complex structure, so it is easier to study the full Andrews-Curtis group FAC(G) generated by AC-transformations on a much simpler set Gk. Our goal here is to investigate the natural epimorphism λ\colon FACk(G) → ACk(G). We show that if G is non-elementary torsion-free hyperbolic, then FACk(G) acts faithfully on every nontrivial orbit of Gk, hence λ\colon FACk(G) → ACk(G) is an isomorphism.

Citations

Related