Hostname: page-component-84b7d79bbc-g5fl4 Total loading time: 0 Render date: 2024-07-31T00:40:34.013Z Has data issue: false hasContentIssue false

On a set of normal subgroups

Published online by Cambridge University Press:  18 May 2009

I. D. Macdonald
Affiliation:
The University Sheffield, 10
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.

The commutator [a, b] of two elements a and b in a group G satisfies the identity

ab = ba[a, b].

The subgroups we study are contained in the commutator subgroup G′, which is the subgroup generated by all the commutators.

The group G is covered by a well-known set of normal subgroups, namely the normal closures {g}G of the cyclic subgroups {g} in G. In a similar way one may associate a subgroup K(g) with each element g, by defining K(g) to be the subgroup generated by the commutators [g, x] as x takes all values in G. These subgroups generate G′ (but do not cover G′ in general), and are normal in G in consequence of the identical relation

(A) [g, x]Y = [g, y]−1[g, xy]

holding for all g, x and y in G. (By ab we mean b−1ab.) It is easy to see that

{g}G = {g, K(g)}.

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 1962

References

1.Macdonald, I. D., On certain varieties of groups, Math. Z. 76 (1961), 270282.CrossRefGoogle Scholar
2.Neumann, B. H., Groups with finite classes of conjugate elements, Proc. London Math. Soc. (3) 1 (1951), 178187.Google Scholar
3.Neumann, B. H., Groups covered by permutable subsets, J. London Math. Soc. 29 (1954), 236248.CrossRefGoogle Scholar
4.Ore, O., Some remarks on commutators, Proc. Amer. Math. Soc. 2 (1951), 307314.CrossRefGoogle Scholar
5.Zassenhaus, H. J., The theory of groups (New York, 1958).Google Scholar