The natural partial order on modules

The Mitsch order is already known as a natural partial order for semigroups and rings. The purpose of this paper is to further study of the Mitsch order on modules by investigating basic properties via endomorphism rings. And so, this study also contributes to the results related to the orders on rings. As a module theoretic analog of the Mitsch order, we show that this order is a partial order on arbitrary modules. Among others, lattice properties of the Mitsch order and the relations between the Mitsch order and the other well-known orders, such as the minus order, the Jones order, the direct sum order, and the space pre-order on modules, are studied. In particular, we prove that the minus order is the Mitsch order and we supply an example to show that the converse does not hold in general.