Relative exact covers
Bican, Ladislav ; Torrecillas, Blas
Commentationes Mathematicae Universitatis Carolinae, Tome 42 (2001), p. 601-607 / Harvested from Czech Digital Mathematics Library
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Recently Rim and Teply [11] found a necessary condition for the existence of $\sigma$-torsionfree covers with respect to a given hereditary torsion theory for the category $R$-mod. This condition uses the class of $\sigma$-exact modules; i.e. the $\sigma$-torsionfree modules for which every its $\sigma$-torsionfree homomorphic image is $\sigma$-injective. In this note we shall show that the existence of $\sigma$-torsionfree covers implies the existence of $\sigma$-exact covers, and we shall investigate some sufficient conditions for the converse.

Publié le : 2001-01-01
Classification:  16D50,  16D90,  16S90,  18E40 
@article{119276,
     author = {Ladislav Bican and Blas Torrecillas},
     title = {Relative exact covers},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     volume = {42},
     year = {2001},
     pages = {601-607},
     zbl = {1068.16039},
     mrnumber = {1883369},
     language = {en},
     url = {http://dml.mathdoc.fr/item/119276}
}

Bican, Ladislav; Torrecillas, Blas. Relative exact covers. Commentationes Mathematicae Universitatis Carolinae, Tome 42 (2001) pp. 601-607. http://gdmltest.u-ga.fr/item/119276/

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