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Centralizer near-rings that are rings

Published online by Cambridge University Press:  09 April 2009

Jutta Hausen
Affiliation:
University of Houston, Houston, Texas 77204-3476, e-mail addresses: [email protected], [email protected]
Johnny A. Johnson
Affiliation:
University of Houston, Houston, Texas 77204-3476, e-mail addresses: [email protected], [email protected]
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Abstract

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Given an R-module M, the centralizer near-ring R (M) is the set of all functions f: M → M with f(xr)= f(x)r for all x ∈ M and r∈R endowed with point-wise addition and composition of functions as multiplication. In general, R(M) is not a ring but is a near-ring containing the endomorphism ring ER(M) of M. Necessary and/or sufficient conditions are derived for R(M) to be a ring. For the case that R is a Dedekind domain, the R-modules M are characterized for which (i) R(M) is a ring; and (ii)R(M) = ER(M). It is shown that over Dedekind domains with finite prime spectrum properties (i) and (ii) are equivalent.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1995

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