Z-Small Submodules and Z-Hollow Modules

A submodule Ϝ of an R-module Ε is called small in Ε if whenever , for some submodule W of Ε , implies . In this paper , we introduce the notion of Ζ-small submodule , where a proper submodule Ϝ of an R-module Ε is said to be Ζ-small in Ε if , such that , then , where is the second singular submodule of Ε . We give some properties of Ζ-small submodules . Moreover , by using this concept , we generalize the notions of hollow modules , supplement submodules, and supplemented modules into Ζ-hollow modules, Ζ-supplement submodules, and Ζ-supplemented modules. We study these concepts and provide some of their relations .

Semi-T-Hollow Modules and Semi-T-Lifting Modules

Let be an associative ring with identity and let be a unitary left -module. Let be a non-zero submodule of .We say that is a semi- - hollow module if for every submodule of such that is a semi- - small submodule ( ). In addition, we say that is a semi- - lifting module if for every submodule of , there exists a direct summand of and such that The main purpose of this work was to develop the properties of these classes of module.

ON T-HOLLOW-LIFITING MODULES

Let be an R-module, and let be a submodule of . A submodule is called -Small submodule () if for every submodule of such that implies that . In our work we give the definition of -coclosed submodule and -hollow-lifiting modules with many properties.

On Jacobson – Small Submodules

Let R be an associative ring with identity and let M be a unitary left R–module. As a generalization of small submodule , we introduce Jacobson–small submodule (briefly J–small submodule ) . We state the main properties of J–small submodules and supplying examples and remarks for this concept . Several properties of these submodules are given . Also we introduce Jacobson–hollow modules ( briefly J–hollow ) . We give a characterization of J–hollow modules and gives conditions under which the direct sum of J–hollow modules is J–hollow . We define J–supplemented modules and some types of modules that are related to J–supplemented modules and introduce properties of this types of modules . Also we discuss the relation between them with examples and remarks are needed in our work.

Strongly K-nonsingular Modules

A submodule N of a module M is said to be s-essential if it has nonzero intersection with any nonzero small submodule in M. In this article, we introduce and study a class of modules in which all its nonzero endomorphisms have non-s-essential kernels, named, strongly -nonsigular. We investigate some properties of strongly -nonsigular modules. Direct summand, direct sums and some connections of such modules are discussed.

Modules Whose Nonzero Endomorphisms Have E-small Kernels

Let $R$ be a commutative ring and $M$ an unital $R$-module. A submodule $L$ of $M$ is called essential submodule of $M$, if $L\cap K\neq\lbrace 0\rbrace$ for any nonzero submodule $K$ of $M$. A submodule $N$ of $M$ is called e-small submodule of $M$ if, for any essential submodule $L$ of $M$, $N+L= M$ implies $L=M$. An $R$-module $M$ is called e-small quasi-Dedekind module if, for each $f\in End_{R}(M),$ $ f\neq 0$ implies $Kerf$ is e-small in $M$. In this paper we introduce the concept of e-small quasi-Dedekind modules as a generalisation of quasi-Dedekind modules, and give some of their properties and characterizations.

SS-Injective Modules and Rings

We introduce and investigate SS-injectivity as a generalization of both soc-injectivity and small injectivity. A right module over a ring is said to be SS- -injective (where is a right -module) if every -homomorphism from a semisimple small submodule of into extends to . A module is said to be SS-injective (resp. strongly SS-injective), if is SS- -injective (resp. SS- -injective for every right -module ). Some characterizations and properties of (strongly) SS-injective modules and rings are given. Some results on soc-injectivity are extended to SS-injectivity.

On S-quasi-Dedekind Modules

Let $R$ be a commutative ring and $M$ an unital $R$-module. A proper submodule $L$ of $M$ is called primary submodule of $M$, if $rm\in L$, where $r\in R$, $m\in M$, then $m\in L$ or $r^{n}M\subseteq L$ for some positive integer $n$. A submodule $K$ of $M$ is called semi-small submodule of $M$ if, $K+L\neq M$ for each primary submodule $L$ of $M$. An $R$-module $M$ is called S-quasi-Dedekind module if, for each $f\in End_{R}(M),$ $ f\neq 0$ implies $Kerf$ semi-small in $M$. In this paper we introduce the concept of S-quasi-Dedekind modules as a generalisation of small quasi-Dedekind modules, and gives some of their properties, characterizations and exemples. Another hand we study the relationships of S-quasi-Dedekind modules with some classes of modules and their endomorphism rings.

Couniform Modules

In this paper we introduce and study a new concept named couniform modules, which is a dual notion of uniform modules, where an R-module M is said to be couniform if every proper submodule N of M is either zero or there exists a proper submodule N1 of N such that is small submodule of (denoted by ) Also many relationships are given between this class of modules and other related classes of modules. Finally, we consider the hereditary property between R-module M and R-module R in case M is couniform.