On the non-existence of right almost split maps

• 成果类型: Article
• 署名作者: Saroch, Jan
• 署名单位: Charles University Prague
• 刊物名称: INVENTIONES MATHEMATICAE
• ISSN/ISSBN: 0020-9910
• DOI: 10.1007/s00222-016-0712-2
• 发表日期: 2017
• 页码: 463-479
• 关键词: free modules; approximations; SEQUENCES

摘要

We show that, over any ring, a module C is the codomain of a right almost split map, if and only if C is finitely presented with a local endomorphism ring. Thus we answer a 40-year-old question by Maurice Auslander.