The purpose of this dissertation is to study weakly projective modules, a concept dual to that
of weakly injective modules. Let M and N be right R-modules. M is called weakly N …

A module M is said to be generalized N-projective (or N-dual ojective) if, for any
epimorphism g: N→ X and any homomorphism f: M→ X, there exist decompositions M …

A module A is called principally self injective if for each principal left ideal L of R and each
homomorphism f: L−→ A with kerf⊇ ann (a) for some a∈ A, there is a homomorphism R−→ …

Let $ R $ be a ring and $ n $ a non-negative integer. In this paper, we first introduce the
concept of $ n $-super finitely copresented $ R $-modules and via these modules, we give a …

A submodule A of a left module B (over an associative ring with 1) is pure if for any right
module F, the natural homomorphism F⊗ A→ F⊗ B is injective. A module C is pure-injective …

This paper extends many conclusions based on phantom envelopes and Ext-phantom
covers of modules, and we find that many important properties still hold after replacing …

A module is said to be P–projective if it is a cokernel of a projective preenvelope. We first
obtain a number of characterizations of P–projectivity. Then we study when the exactness of …

A module is called nilpotent-invariant if it is invariant under any nilpotent endomorphism of
its injective envelope [MT Koşan and TC Quynh, Nilpotent-invaraint modules and rings …

The primary goal of this paper is to investigate the structure of irreducible monomorphisms to
and irreducible epimorphisms from finitely generated free modules over a noetherian local …