1. Department of Mathematics , The Ohio State University , Lima , Ohio , USA yousif.1@osu.edu;3. Faculty of Science, Department of Mathematics , Cairo University , Giza , Egypt
Abstract:
A right R-module M is called a D3-module, if M1 and M2 are direct summands of M with M = M1 + M2, then M1 ∩ M2 is a direct summand of M. Following the work of Bass on projective covers, we introduce the notion of D3-covers and provide new characterizations of several well-known classes of rings in terms of D3-modules and D3-covers.