Cotorsion theories Page 1 Pacific Journal of Mathematics COTORSION THEORIES STEPHEN
DALE BRONN Vol. 48, No. 2 April 1973 Page 2 PACIFIC JOURNAL OF MATHEMATICS Vol …

The concept of cotorsion was first introduced in the category of Abelian groups (Fuchs [l]).
Matlis [5], studied the cotorsion modules over integral domains. Henderson and Orzech [4] …

Let R be a right perfect ring, and let (ℱ, 𝒞) be a cotorsion theory in the category of right R-
modules ℳ R. In this article, it is shown that every right R-module has a superfluous ℱ-cover …

nX-Projective Modules, nX-Injective Modules, Cotorsion Theories Page 1 Int. J. Contemp. Math.
Sciences, Vol. 5, 2010, no. 56, 2753 - 2762 n-X-Projective Modules, n-X-Injective Modules …

Let $ R $ be a ring with identity and let $\mathcal {M} _R $ be the category of right $ R $-
modules. In this article, we study some relations between torsion theories and cotorsion …

Let R be a ring, M a right R-module, and na fixed non-negative integer. M is called n-
cotorsion if for any flat right R-module N. M is said to be n-flat if for any n-cotorsion right R …

Throughout the following note R will denote an associative ring with unit element 1. We shall
denote by R-mod [resp. mod-R] the category of all unitary left [resp. right] R-modules …

Let R be a ring, na fixed nonnegative integer and FP n (F n) the class of all left (right) R-
modules of FP-injective (flat) dimensions at most n. A left R-module M (resp., right R-module …

Let R be an associative ring with unit element. Mod-R and R-Mod will denote the categories
of unitary right and left R-modules, respectively, and all modules are assumed to be in Mod …

In this survey article, we introduce the properties of the cotorsion theory and show how to
construct the homology theory for all cotorsion theories. This can be considered the final …