Manfred Dugas, Shalom Feigelstock

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


A ring R is called an E-ring if every endomorphism of R+; the additive group of R; is multiplication on the left by an element of R: This is a well known notion in the theory of abelian groups. We want to change the “E” as in endomorphisms to an “A” as in automorphisms: We define a ring to be an A-ring if every automorphism of R+ is multiplication on the left by some element of R: We show that many torsion-free finite rank (tffr) A-rings are actually E-rings. While we have an example of a mixed A-ring that is not an E-ring, it is still open if there are any tffr A-rings that are not E-rings. We will employ the Strong Black Box [5] to construct large integral domains that are A-rings but not E-rings.

Original languageEnglish
Pages (from-to)277-292
Number of pages16
JournalColloquium Mathematicum
Issue number2
StatePublished - 2003

Bibliographical note

Publisher Copyright:
© 2003, Instytut Matematyczny. All rights reserved.


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