Hostname: page-component-76fb5796d-r6qrq Total loading time: 0 Render date: 2024-04-28T01:43:31.597Z Has data issue: false hasContentIssue false

Perfect semigroups

Published online by Cambridge University Press:  20 January 2009

John Fountain
Affiliation:
University of York, Heslington, York Y01 5DD
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.

A semigroup S with identity is (left) perfect if every unitary left S-system has a projective cover. This is the semigroup analogue of the definition of left perfect rings introduced in (1). The investigation of perfect semigroups was initiated by Isbell (4), who proved that a semigroup is perfect if and only if it satisfies two conditions referred to as conditions A and D.

Type
Research Article
Copyright
Copyright © Edinburgh Mathematical Society 1976

References

REFERENCES

(1) Bass, H., Finitistic dimension and a homological generalization of semi-primary rings, Trans. Amer. Math. Soc. 95 (1960), 466488.CrossRefGoogle Scholar
(2) Björk, J-E., Rings satisfying a minimum condition on principal ideals, J. Reine Angew. Math. 236 (1969), 112119.Google Scholar
(3) Clifford, A. H. and Preston, G. B., The algebraic theory of semigroups, Vol. II (Math. Surveys No. 7, Amer. Math. Soc, 1967).Google Scholar
(4) Isbell, J. R., Perfect monoids, Semigroup Forum 2 (1971), 95118.CrossRefGoogle Scholar
(5) Kil'p, M., On homological classification of monoids. Siber. Math. J. 13 (1972), 396401.CrossRefGoogle Scholar
(6) Knauer, U., Projectivity of acts and Morita equivalence of monoids, Semigroup Forum 3 (1972), 359370.CrossRefGoogle Scholar
(7) Stenström, B., Flatness and localization over monoids, Math. Nachr. 48 (1971), 315334.CrossRefGoogle Scholar