Generalized triangle groups, expanders, and a problem of Agol and Wise
Group Theory
2018-05-30 v2 Geometric Topology
Abstract
Answering a question asked by Agol and Wise, we show that a desired stronger form of Wise's malnormal special quotient theorem does not hold. The counterexamples are generalizations of triangle groups, built using the Ramanujan graphs constructed by Lubotzky--Phillips--Sarnak.
Cite
@article{arxiv.1702.08200,
title = {Generalized triangle groups, expanders, and a problem of Agol and Wise},
author = {Alexander Lubotzky and Jason Fox Manning and Henry Wilton},
journal= {arXiv preprint arXiv:1702.08200},
year = {2018}
}
Comments
12 pages, 2 figures. V2 incorporates changes suggested by the referee. This is the final version accepted for publication