On Strongly Copure Flat Modules and Copure Flat Dimensions

摘要

Let R be a left coherent ring. We first prove that a right R-module M is strongly copure flat if and only if Ext~i(M, C) = 0 for all flat cotorsion right R-modules C and i ≥ 1. Then we define and investigate copure flat dimensions of left coherent rings. Finally, we give some new characterizations of n-FC rings.