The CI problem for infinite groups
dc.contributor.author | Morris, Joy | |
dc.date.accessioned | 2018-06-29T17:50:18Z | |
dc.date.available | 2018-06-29T17:50:18Z | |
dc.date.issued | 2016 | |
dc.description | Sherpa Romeo green journal: open access | en_US |
dc.description.abstract | A finite group G is a DCI-group if, whenever S and S0 are subsets of G with the Cayley graphs Cay(G,S) and Cay(G,S0) isomorphic, there exists an automorphism ϕ of G with ϕ(S) = S0. It is a CI-group if this condition holds under the restricted assumption that S = S−1. We extend these definitions to infinite groups, and make two closely-related definitions: an infinite group is a strongly (D)CIf-group if the same condition holds under the restricted assumption that S is finite; and an infinite group is a (D)CIf-group if the same condition holds whenever S is both finite and generates G. We prove that an infinite (D)CI-group must be a torsion group that is not locallyfinite. We find infinite families of groups that are (D)CIf-groups but not strongly (D)CIf-groups, and that are strongly (D)CIf-groups but not (D)CI-groups. We discuss which of these properties are inherited by subgroups. Finally, we completely characterise the locally-finite DCI-graphs on Zn. We suggest several open problems related to these ideas, including the question of whether or not any infinite (D)CIgroup exists. | en_US |
dc.description.peer-review | Yes | en_US |
dc.identifier.citation | Morris, J. (2016). The CI problem for infinite groups. Electronic Journal of Combinatorics, 23(4), 4.37 | en_US |
dc.identifier.uri | https://hdl.handle.net/10133/5145 | |
dc.language.iso | en_US | en_US |
dc.publisher | Electronic Journal of Combinatorics | en_US |
dc.publisher.department | Department of Mathematics and Computer Science | en_US |
dc.publisher.faculty | Arts and Science | en_US |
dc.publisher.institution | University of Lethbridge | en_US |
dc.subject | Caley | en_US |
dc.subject | Isomorphisms | en_US |
dc.subject | Infinite groups | en_US |
dc.subject | CI-problem | en_US |
dc.subject | CI-group | en_US |
dc.subject | CI-graph | en_US |
dc.subject.lcsh | Isomorphisms (Mathematics) | |
dc.subject.lcsh | Caley graphs | |
dc.subject.lcsh | Combinatorial analysis | |
dc.subject.lcsh | Group theory | |
dc.title | The CI problem for infinite groups | en_US |
dc.type | Article | en_US |