Let n≥ 1 be an integer. A functor F∈(mod-R, Ab) is called n-strongly FP-injective if F is
isomorphic to some functor-⊗ M in (mod-R, Ab) with M an FP n-injective left R-module. A …

For a Quillen exact category CC endowed with two exact structures DD and EE such that E
⊆ DE⊆ D, an object X of CC is called E E-divisible (respectively E E-flat) if every short exact …

Given a ring R, the categories of covariant additive functors (mod-R, Ab) and contravariant
additive functors ((mod-R) op, Ab) from the category mod-R of finitely presented right R …

In this paper, we investigate the homological properties of the functor categories (mod− R,
Ab) and ((mod− R) op, Ab). Some new homological dimensions in these functor categories …

We introduce weakly FP-injective and weakly flat functors, and we show that a right R-
module K is FP-injective if and only if (−, K) is a flat weakly FP-injective functor in ((\rm mod …

The category of morphisms of R-modules is an expansion of the category of R-modules.
Using some special morphisms of modules such as phantom, Ext-phantom, flat and …

Let R be an associative ring with identity. Denote by ((R-mod) op, Ab) the category
consisting of contravariant functors from the category of finitely presented left R-modules R …