Some Results on Self-Injective Rings and Σ-CS Rings

Abstract

A module M is CS if every submodule of M is essential in a direct summand of M. In this note we use the CS condition to provide conditions for semiperfect rings to be self-injective. Further we show that every finitely generated CS right module over a right semi-artinian ring has finite uniform dimension. Using this, we prove that if R is a right semi-artinian ring such that is CS, then is also CS for any set A. Moreover, R is then right and left artinian.