Abstract
E-rings are a well known notion in the theory of abelian groups. They are those rings R such that End (R+), the ring of endomorphisms of the additive group of R, is as small as possible, i.e. End (R+)=Rℓ, where Rℓ={x↦ax:a∈R}(. We generalize the notion of E-rings by calling a ring R an almost- E-ring, or AE-ring for short, if End (R+) is a radical extension of Rℓ, i.e. for each φ∈End (R+) there is some natural number n such that φn∈Rℓ. We will show that this notion does not lead to a new class of rings. It turns out that all AE-rings are actually E-rings. Our proof utilizes Herstein’s Hypercenter Theorem.
Original language | English |
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Pages (from-to) | 239-246 |
Number of pages | 8 |
Journal | Rendiconti del Seminario Matematico dell 'Universita' di Padova/Mathematical Journal of the University of Padova |
Volume | 111 |
State | Published - 2004 |
Bibliographical note
Publisher Copyright:© 2004, Universita di Padova. All rights reserved.