Relative injectivity and CS-modules

In this paper we show that a direct decomposition of modules M⊕N, with N homologically independent to the injective hull of M, is a CS-module if and only if N is injective relative to M and both of M and N are CS-modules. As an application, we prove that a direct sum of a non-singular semisimple mod...

Full description

Saved in:
Bibliographic Details
Main Author: Mahmoud Ahmed Kamal
Format: Article
Language:English
Published: Wiley 1994-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Subjects:
Online Access:http://dx.doi.org/10.1155/S0161171294000931
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849305205474066432
author Mahmoud Ahmed Kamal
author_facet Mahmoud Ahmed Kamal
author_sort Mahmoud Ahmed Kamal
collection DOAJ
description In this paper we show that a direct decomposition of modules M⊕N, with N homologically independent to the injective hull of M, is a CS-module if and only if N is injective relative to M and both of M and N are CS-modules. As an application, we prove that a direct sum of a non-singular semisimple module and a quasi-continuous module with zero socle is quasi-continuous. This result is known for quasi-injective modules. But when we confine ourselves to CS-modules we need no conditions on their socles. Then we investigate direct sums of CS-modules which are pairwise relatively inective. We show that every finite direct sum of such modules is a CS-module. This result is known for quasi-continuous modules. For the case of infinite direct sums, one has to add an extra condition. Finally, we briefly discuss modules in which every two direct summands are relatively inective.
format Article
id doaj-art-0235c8793e564c0b98f6f18f7598f4e5
institution Kabale University
issn 0161-1712
1687-0425
language English
publishDate 1994-01-01
publisher Wiley
record_format Article
series International Journal of Mathematics and Mathematical Sciences
spelling doaj-art-0235c8793e564c0b98f6f18f7598f4e52025-08-20T03:55:32ZengWileyInternational Journal of Mathematics and Mathematical Sciences0161-17121687-04251994-01-0117466166610.1155/S0161171294000931Relative injectivity and CS-modulesMahmoud Ahmed Kamal0Ain Shams University, Faculty of Education, Mathematics Department, Heliopolis, Cairo, EgyptIn this paper we show that a direct decomposition of modules M⊕N, with N homologically independent to the injective hull of M, is a CS-module if and only if N is injective relative to M and both of M and N are CS-modules. As an application, we prove that a direct sum of a non-singular semisimple module and a quasi-continuous module with zero socle is quasi-continuous. This result is known for quasi-injective modules. But when we confine ourselves to CS-modules we need no conditions on their socles. Then we investigate direct sums of CS-modules which are pairwise relatively inective. We show that every finite direct sum of such modules is a CS-module. This result is known for quasi-continuous modules. For the case of infinite direct sums, one has to add an extra condition. Finally, we briefly discuss modules in which every two direct summands are relatively inective.http://dx.doi.org/10.1155/S0161171294000931injective modulesself-injective ringsand generalization.
spellingShingle Mahmoud Ahmed Kamal
Relative injectivity and CS-modules
International Journal of Mathematics and Mathematical Sciences
injective modules
self-injective rings
and generalization.
title Relative injectivity and CS-modules
title_full Relative injectivity and CS-modules
title_fullStr Relative injectivity and CS-modules
title_full_unstemmed Relative injectivity and CS-modules
title_short Relative injectivity and CS-modules
title_sort relative injectivity and cs modules
topic injective modules
self-injective rings
and generalization.
url http://dx.doi.org/10.1155/S0161171294000931
work_keys_str_mv AT mahmoudahmedkamal relativeinjectivityandcsmodules