对偶模的投射性与内射性

PROJECTIVITY AND INJECTIVITV OF DUAL MODULES

本文主要证明了如下结果: (1)WD(R)≤1且R为右fp-内射对任意左f.p.(finitely Ptesented)模M,Mo为fp-内射。 (2)R为左半遗传右fP-内射环时任意左(f.g.)模M,M为fp-内射若0→N_R→R^m→R^n为正合例,则N为fp-内射。 (3)R为正则右内射环对任意左f.P.(f.g.)模M,M为内射。

In this paper, fp-injectivity; injectivity and Projectivity of dual modules are considered。 We characterize the three rings:(1)WD(R)≤land R is right fp-injective;(2)R is left Semi-hereditary right fp-injective;(3)R is regular right injective ring, by using dual modules。