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Semiregular Modules and Rings

Published online by Cambridge University Press:  20 November 2018

W. K. Nicholson*
Affiliation:
University of Calgary, Calgary, Alberta
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Mares [9] has called a projective module semiperfect if every homomorphic image has a projective cover and has shown that many of the properties of semiperfect rings can be extended to these modules. More recently Zelmanowitz [16] has called a module regular if every finitely generated submodule is a projective direct summand. In the present paper a class of semiregular modules is introduced which contains all regular and all semiperfect modules. Several characterizations of these modules are given and a structure theorem is proved. In addition several theorems about regular and semiperfect modules are extended.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1976

References

1. Armendariz, E. P. and Fisher, J. W., Idealizers in rings, Notices Amer. Math. Soc. 21 (1974), A457.Google Scholar
2. Bass, H., Finitistic dimension and a homological generalization of semiprimary rings, Trans. Amer. Math. Soc. 95 (1960), 466488.Google Scholar
3. Cateforis, V. C. and Sandomierski, F. L., The singular submodule splits off, J. Algebra 10 (1968), 149165.Google Scholar
4. Cukerman, G. M., Rings of endomorphisms of free modules, Sibirsk. Mat. Z. 7 (1966), 11611167 (Russian).Google Scholar
5. Fieldhouse, D. J., Pure theories, Math. Ann. 184 (1969), 118.Google Scholar
6. Jansen, W. G., F-semiperfect rings and modules and quasi-simple modules, Notices Amer. Math. Soc. 20 (1973), A-564.Google Scholar
7. Kaplansky, I., Projective modules, Annals of Math. 68 (1958), 372377.Google Scholar
8. Kasch, Fr. and Mares, E. A., Eine Kennzeichnung Semi-perfekter Moduln, Nagoya Math. J. 27 (1966), 525529.Google Scholar
9. Mares, E. A., Semi-perfect modules, Math. Zeitschr. 82 (1963), 347360.Google Scholar
10. Mueller, B. J., On semiperfect rings, Illinois J. Math. 14 (1970), 464467.Google Scholar
11. Oberst, U. and H.-J. Schneider, Die Struktur von projektiven Moduln, Inventiones Math. 13 (1971), 295304.Google Scholar
12. Shanny, R. F., Regular endomorphism rings of free modules, J. London Math. Soc. (2) 4 (1971), 353354.Google Scholar
13. Ware, R., Endomorphism rings of projective modules, Trans. Amer. Math. Soc. 155 (1971), 233256.Google Scholar
14. Warfield, R. B., Exchange rings and decompositions of modules, Ann. Math. 199 (1972), 3136.Google Scholar
15. W∞ds, S. M., Some results on semi-perfect group rings, Can. J. Math. 26 (1974), 121129.Google Scholar
16. Zelmanowitz, J., Regular modules, Trans. Amer. Math. Soc. 163 (1972), 341355.Google Scholar