Study of Semi-projective Retractable Modules

• 来源期刊: 代数集刊(英文版)
• 关键词: retractable semi-projective weakly compressible
• 年，卷（期）: 2007,（3）
• 页码范围: 489-496
• 页数: 8页
• 语种: 英文

摘要

For a semi-projective retractable module MR with endomorphism ring S,we prove u.dim MR = u.dim Ss,and find necessary and sufficient conditions on M in order that S be respectively semiprime,right nonsingular,finitely cogenerated,cocyclic,or weakly co-Hopfian.Precise descriptions of the right singular ideal of S and the socle of M are given,and in addition if S is a semiprime ring,it is shown that MR is FI-extending if and only if Ss is FI-extending.