Hostname: page-component-848d4c4894-2pzkn Total loading time: 0 Render date: 2024-05-14T12:54:29.121Z Has data issue: false hasContentIssue false

Semigroups of high rank

Published online by Cambridge University Press:  20 January 2009

Emilia Giraldes
Affiliation:
Departamento de Matemática Faculdade de CiênciasUniversidade de Lisboa1700 Lisboa, Portugal
John M. Howie
Affiliation:
Mathematical Institute University of St AndrewsNorth HaughSt Andrews, Scotland
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.

By the rank r(S) of a finite semigroup S we shall mean the minimum cardinality of a set of generators ofS. For a group G, as remarked in [3], one has r(G)≦log2|G|, the bound being attained when G is an elementary abelian 2-group. By contrast, we shall see that there exist finite semigroups S for which r(S)≧|S| – 1. In the hope that it will not be considered too whimsical, we shall refer to a finite semigroup S of maximal rank (i.e. for which r(S) = |S|) as royal; a semigroup of next-to-maximal rank (i.e. for which r(S) = |S|–1) will be called noble.

Type
Research Article
Copyright
Copyright © Edinburgh Mathematical Society 1985

References

REFERENCES

1.Clifford, A. H., Semigroups admitting relative inverses, Ann. of Math. 42 (1941), 10371049.CrossRefGoogle Scholar
2.Howie, J. M., An introduction to semigroup theory (Academic Press, London, 1976).Google Scholar
3.Howie, J. M., Embedding semigroups in semibands: some arithmetical results, Quart. J. Math. Oxford (2) 32 (1981), 323337.CrossRefGoogle Scholar
4.McLean, D., Idempotent semigroups, American Math. Monthly 61 (1954), 110113.CrossRefGoogle Scholar
5.Petrich, M., Lectures in semigroups (Akademie-Verlag, Berlin, 1977).CrossRefGoogle Scholar