Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-12T21:33:54.846Z Has data issue: false hasContentIssue false

Subgroups of HNN Groups and Groups with one Defining Relation

Published online by Cambridge University Press:  20 November 2018

A. Karrass
Affiliation:
York University, Toronto, Ontario
D. Solitar
Affiliation:
York University, Toronto, Ontario
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

HNN groups have appeared in several papers, e.g., [3; 4; 5; 6; 8]. In this paper we use the results in [6] to obtain a structure theorem for the subgroups of an HNN group and give several applications.

We shall use the terminology and notation of [6]. In particular, if K is a group and {φi} is a collection of isomorphisms of subgroups {Li} into K, then we call the group

1

the HNN group with base K, associated subgroups { Lii(Li)} and free part the group generated by t1, t2, …. (We usually denote φi(Li) by Mi or L–i.) The notion of a tree product as defined in [6] will also be needed.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1971

References

1. Baumslag, G., On generalized free products of torsion-free nilpotent groups. I (to appear in Illinois J. Math.).Google Scholar
2. Baumslag, G., Karrass, A. and Solitar, D., Torsion-free groups and amalgamated products, Proc. Amer. Math. Soc. 24 (1970), 688690.Google Scholar
3. Britton, J. L., The word problem, Ann. of Math. 84 (1963), 1632.Google Scholar
4. Higman, G., Subgroups of finitely presented groups, Proc. Roy. Soc. London Ser. A 262 (1961), 455475.Google Scholar
5. Higman, G., Neumann, B. H. and Neumann, H., Embedding theorems for groups, J. London Math. Soc. 24 (1949), 247254.Google Scholar
6. Karrass, A. and Solitar, D., The subgroups of a free product of two groups with an amalgamated subgroup, Trans. Amer. Math. Soc. 149 (1970), 227255.Google Scholar
7. Magnus, W., Karrass, A. and Solitar, D., Combinatorial group theory, Pure and Appl. Math., Vol. 13 (Interscience, New York 1966).Google Scholar
8. Moldavanski, D. I., Certain subgroups of groups with one defining relation, Siberian Math. J. 8 (1967), 13701384.Google Scholar
9. Newman, B. B., Some aspects of one relator groups (to appear).Google Scholar
10. Neumann, B. H., An essay on free products of groups with amalgamations, Philos. Trans. Roy. Soc. London Ser. A 246 (1954), 503554.Google Scholar