Elementary subgroups of the free group are free factors - a new proof
Logic
2019-03-15 v1 Group Theory
Abstract
In this note we give a new proof of the fact that an elementary subgroup (in the sense of first-order theory) of a non abelian free group must be a free factor. The proof is based on definability of orbits of elements of under automorphisms of fixing a large enough subset of .
Keywords
Cite
@article{arxiv.1903.05876,
title = {Elementary subgroups of the free group are free factors - a new proof},
author = {Chloé Perin},
journal= {arXiv preprint arXiv:1903.05876},
year = {2019}
}