|
|||||
|
|
Projective and indecomposableS-acts |
|
| Authors: | Chen Yuqun K P Shum |
| Institution: | 1. Department of Mathematics, South China Normal University, 510631, Guangzhou, China 2. Department of Mathematics, the Chinese University of Hong Kong, Hong Kong, China 3. Department of Mathematics, the Chinese University of Hong Kong, Hong Kong, China |
| Abstract: | LetS be a semigroup andE the set of all idempotents inS. LetS-Act be the category of allS-acts. LetC be a full subcategory ofS-Act which containss S and is closed under coproducts and summands. It is proved that, inC, anS-actP is projective and unitary if and only ifP≅ ∐ jϕ I Se i ,e i ϕE. In particular,P is a projective, indecomposable and unitary object if and only ifP ≅Se for somee ∈E. These generalize some results obtained by Knauer and Talwar. |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ | |