If R is an associative ring with identity, a theory of minimal flat resolutions is developed in the
category ((R-mod) op, Ab) of contravariant functors G:(R-mod) op→ Ab from the category R …

A morphism f: M→ N of left R-modules is a phantom morphism if for any morphism g: A→ M,
with A finitely presented, the composition fg factors through a projective module …

An additive functor from the category of flat right R‐modules to the category of abelian
groups is continuous if it is isomorphic to a functor of the form−⊗ RM, where M is a left R …

Let R be an associative ring with identity. A right R-module M is called cotorsion if Ext"(F,
M)= 0 for every flat right R-module F. These modules were introduced by Harrison [21] in the …

The use of category equivalences for the study of endomorphism rings stems from the Morita
theorem. In a sense, this theorem can be viewed as stating that if P is a finitely generated …

In a series of papers additive subbifunctors $ F $ of the bifunctor $\operatorname {Ext} _
{\Lambda}(,) $ are studied in order to establish a relative homology theory for an artin …

The aim of this paper is to study a property of a special kind of exact functors and give some
applications to projective modules and injective modules. In section 1 we introduce the …

The goal of this work is to develop a functional transfer of properties between a module A
and the category* M* E of right modules over its endomorphism ring* E that is more sensitive …

Cartan and Eilenberg [1, p. 961 call a functor T of several variables right balanced if T
becomes an exact functor of the remaining variables when any covariant variable is …

We prove the following results for the subcategories of an abelian category: 1) The full
subcategory whose objects are kernels of the maps between two covariantly finite …