On δ-semiperfect modules
A submodule N of a module M is δ-small in M if N+X≠M for any proper submodule X of M with M∕X singular. A projective δ-cover of a module M is a projective module P with an epimorphism to M whose kernel is δ-small in P. A module M is called δ-semiperfect if every factor module of M has a projective δ...
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Published in | Communications in algebra Vol. 46; no. 11; pp. 4965 - 4977 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Taylor & Francis
02.11.2018
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Subjects | |
Online Access | Get full text |
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Summary: | A submodule N of a module M is δ-small in M if N+X≠M for any proper submodule X of M with M∕X singular. A projective δ-cover of a module M is a projective module P with an epimorphism to M whose kernel is δ-small in P. A module M is called δ-semiperfect if every factor module of M has a projective δ-cover. In this paper, we prove various properties, including a structure theorem and several characterizations, for δ-semiperfect modules. Our proofs can be adapted to generalize several results of Mares [
8
] and Nicholson [
11
] from projective semiperfect modules to arbitrary semiperfect modules. |
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ISSN: | 0092-7872 1532-4125 |
DOI: | 10.1080/00927872.2018.1459650 |