English

Largeness of LERF and 1-relator groups

Group Theory 2008-03-28 v1

Abstract

We consider largeness of groups given by a presentation of deficiency 1, where the group is respectively free-by-cyclic, LERF or 1-relator. We give the first examples of (finitely generated free)-by-(infinite cyclic) word hyperbolic groups which are large, show that a LERF deficiency 1 group with first Betti number at least 2 is large or the integers times the integers, and show that 2-generator 1-relator groups where the relator has height 1 obey the dichotomy that either the group is large or all its finite images are metacyclic.

Keywords

Cite

@article{arxiv.0803.3805,
  title  = {Largeness of LERF and 1-relator groups},
  author = {Jack Button},
  journal= {arXiv preprint arXiv:0803.3805},
  year   = {2008}
}

Comments

33 pages; contains a problem list on pages 22 to 28

R2 v1 2026-06-21T10:24:45.686Z