On Semiregular Endomorphism Rings and the Dual of Yamagata’s Theorem
Tamer Koşan
,
Truong Cong Quynh
Abstract
In this paper, we characterize a module whose endomorphism ring is $\delta$-semiregular. For a right $R$-module $M$, we also obtained dual Yamagata’s theorem on the set $\nabla_{\delta}=\{f\in End(M)|f(M) \text{ is } \delta \text{ small in } M\}$.