co-* s -modules

Abstract

J. Wei recently proposed a concept of * s -modules which is another generalization of * -modules besides * n -modules [J. Algebra, 2005, 291: 312-324]. In this paper, we consider the co- * s -modules and give some characterizations and properties. It is found that the class of co- * s -modules contains co-selfsmall injective cogenerators. The relations between co- * smodules and co- * n -modules are also considered.