We say a left R-module M is ecg-extending if every essentially countably generated submodule of M is essential in a direct summand of M. After giving some basic properties of ecg-extending modules, we show that for a ...We say a left R-module M is ecg-extending if every essentially countably generated submodule of M is essential in a direct summand of M. After giving some basic properties of ecg-extending modules, we show that for a nonsingular ring R, all left R-modules are ecg- extending if and only if all left R-modules are extending. We also characterize noetherian rings and artinian semisimple rings via ecg-quasi-continuous modules.展开更多
基金the National Natural Science Foundation of China (10171082)the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE, P.R.C.
文摘We say a left R-module M is ecg-extending if every essentially countably generated submodule of M is essential in a direct summand of M. After giving some basic properties of ecg-extending modules, we show that for a nonsingular ring R, all left R-modules are ecg- extending if and only if all left R-modules are extending. We also characterize noetherian rings and artinian semisimple rings via ecg-quasi-continuous modules.