On a conjecture of Karrass and Solitar
Group Theory
2013-11-08 v3
Abstract
We settle an old conjecture of Karrass and Solitar by proving that a finitely generated subgroup of a non-trivial free product has finite index if and only if it intersects non-trivially each non-trivial normal subgroup of . This holds, more generally, for subgroups of finite Kurosh rank.
Keywords
Cite
@article{arxiv.1303.7279,
title = {On a conjecture of Karrass and Solitar},
author = {Benjamin Steinberg},
journal= {arXiv preprint arXiv:1303.7279},
year = {2013}
}
Comments
Changed the intro to reflect comments by G. Arzhantseva on the time frame and history of her work. Referee's corrections implemented