Invariable Generation of Certain Branch Groups
(2025) In Bulletin of the Malaysian Mathematical Sciences Society 48(4).- Abstract
Let G be a group. Then S⊆G is an invariable generating set of G if every subset S′ obtained from S by replacing each element with a conjugate is also a generating set of G. We investigate invariable generation among key examples of branch groups. In particular, we prove that all generating sets of the torsion Grigorchuk groups, of the branch Grigorchuk-Gupta-Sidki groups and of the torsion multi-EGS groups (which are natural generalisations of the Grigorchuk-Gupta-Sidki groups) are invariable generating sets. Furthermore, for the first Grigorchuk group and the torsion Grigorchuk-Gupta-Sidki groups, every finitely generated subgroup has a finite invariable generating set. Our results apply to finitely generated groups in MN, the class of... (More)
Let G be a group. Then S⊆G is an invariable generating set of G if every subset S′ obtained from S by replacing each element with a conjugate is also a generating set of G. We investigate invariable generation among key examples of branch groups. In particular, we prove that all generating sets of the torsion Grigorchuk groups, of the branch Grigorchuk-Gupta-Sidki groups and of the torsion multi-EGS groups (which are natural generalisations of the Grigorchuk-Gupta-Sidki groups) are invariable generating sets. Furthermore, for the first Grigorchuk group and the torsion Grigorchuk-Gupta-Sidki groups, every finitely generated subgroup has a finite invariable generating set. Our results apply to finitely generated groups in MN, the class of groups whose maximal subgroups are all normal. We then obtain that any 2-generated group in MN is almost 32-generated, and end by applying this observation to generating graphs.
(Less)
- author
- Cox, Charles Garnet and Thillaisundaram, Anitha LU
- organization
- publishing date
- 2025-07
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Branch groups, Generating subgraph, Groups acting on rooted trees, Invariable generation, Maximal subgroups
- in
- Bulletin of the Malaysian Mathematical Sciences Society
- volume
- 48
- issue
- 4
- article number
- 107
- publisher
- Springer Singapore
- external identifiers
-
- scopus:105005710619
- ISSN
- 0126-6705
- DOI
- 10.1007/s40840-025-01895-5
- language
- English
- LU publication?
- yes
- id
- 853e6690-ba4b-46f1-8c3a-6ae409be86e6
- date added to LUP
- 2025-07-16 13:34:07
- date last changed
- 2025-07-16 13:35:25
@article{853e6690-ba4b-46f1-8c3a-6ae409be86e6,
abstract = {{<p>Let G be a group. Then S⊆G is an invariable generating set of G if every subset S′ obtained from S by replacing each element with a conjugate is also a generating set of G. We investigate invariable generation among key examples of branch groups. In particular, we prove that all generating sets of the torsion Grigorchuk groups, of the branch Grigorchuk-Gupta-Sidki groups and of the torsion multi-EGS groups (which are natural generalisations of the Grigorchuk-Gupta-Sidki groups) are invariable generating sets. Furthermore, for the first Grigorchuk group and the torsion Grigorchuk-Gupta-Sidki groups, every finitely generated subgroup has a finite invariable generating set. Our results apply to finitely generated groups in MN, the class of groups whose maximal subgroups are all normal. We then obtain that any 2-generated group in MN is almost 32-generated, and end by applying this observation to generating graphs.</p>}},
author = {{Cox, Charles Garnet and Thillaisundaram, Anitha}},
issn = {{0126-6705}},
keywords = {{Branch groups; Generating subgraph; Groups acting on rooted trees; Invariable generation; Maximal subgroups}},
language = {{eng}},
number = {{4}},
publisher = {{Springer Singapore}},
series = {{Bulletin of the Malaysian Mathematical Sciences Society}},
title = {{Invariable Generation of Certain Branch Groups}},
url = {{http://dx.doi.org/10.1007/s40840-025-01895-5}},
doi = {{10.1007/s40840-025-01895-5}},
volume = {{48}},
year = {{2025}},
}