Notes on cotorsion modules

被引:34
作者
Mao, LX [1 ]
Ding, NQ
机构
[1] Nanjing Univ, Dept Math, Nanjing 210093, Peoples R China
[2] Nanjing Inst Technol, Dept Basic Course, Nanjing, Peoples R China
基金
高等学校博士学科点专项科研基金; 中国国家自然科学基金;
关键词
cotorsion module; cotorsion envelope; flat cover; perfect ring; von Neumann regular ring;
D O I
10.1081/AGB-200041029
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
Let R be a ring. A right R-module C is called cotorsion if Ext(R)(1)(F, C) = 0 for any flat right R-module F. In this paper, we first give some results on cotorsion envelopes that are analogous to those on injective envelopes. Then we characterize those rings R for which every cotorsion right R-module is A-injective, where A is a nonemptry collection of right ideals of R. Finally, some new characterizations of right perfect rings and von Neumann regular rings are given.
引用
收藏
页码:349 / 360
页数:12
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