English

A note on test elements for monomorphisms of free groups

Group Theory 2026-05-22 v2

Abstract

A word in a group is called a test element if any endomorphism fixing it is necessarily an automorphism. In this note, we give a sufficient condition in geometry to construct test elements for monomorphisms of a free group, by using the Whitehead graph and the action of the free group on its Cayley graph.

Keywords

Cite

@article{arxiv.2408.13449,
  title  = {A note on test elements for monomorphisms of free groups},
  author = {Dongxiao Zhao and Qiang Zhang},
  journal= {arXiv preprint arXiv:2408.13449},
  year   = {2026}
}

Comments

8 pages, 3 figures

R2 v1 2026-06-28T18:22:44.735Z