Folding sequences
摘要
Bestvina and Feighn showed that a morphism S --> T between two simplicial trees that commutes with the action of a group G can be written as a product of elementary folding operations. Here a more general morphism between simplicial trees is considered, which allow different groups to act on S and T. It is shown that these morphisms can again be written as a product of elementary operations: the Bestvina-Feighn folds plus the so-called `vertex morphisms'. Applications of this theory are presented. Limits of infinite folding sequences are considered. One application is that a finitely generated inaccessible group must contain an infinite torsion subgroup.
引用
@article{arxiv.math/9810192,
title = {Folding sequences},
author = {M. J. Dunwoody},
journal= {arXiv preprint arXiv:math/9810192},
year = {2016}
}
备注
20 pages. Published copy, also available at http://www.maths.warwick.ac.uk/gt/GTMon1/paper7.abs.html