Original Article
Kyungpook Mathematical Journal 2011; 51(1): 1-10
Published online March 23, 2011
Copyright © Kyungpook Mathematical Journal.
Normal Pairs of Going-down Rings
David Earl Dobbs1, Jay Allen Shapiro2
1Department of Mathematics, University of Tennessee, Knoxville, Tennessee 37996- 0614, USA
2Department of Mathematics, George Mason University, Fairfax, Virginia 22030- 4444, USA
Received: March 23, 2011; Revised: March 23, 2011; Accepted: March 23, 2011
Let $(R,T)$ be a normal pair of commutative rings (i.e., $R subseteq T$ is a unital extension of commutative rings, not necessarily integral domains, such that $S$ is integrally closed in $T$ for each ring $S$ such that $R subseteq S subseteq T$) such that the total quotient ring of $R$ is a von Neumann regular ring. Let $mathcal{P}$ be one of the following ring-theoretic properties: going-down ring, extensionally going-down (EGD) ring, locally divided ring. Then $R$ has $mathcal{P}$ if and only if $T$ has $mathcal{P}$. An example shows that the ``if" part of the assertion fails if $mathcal{P}$ is taken to be the ``divided domain" property.
Keywords: Normal pair, prime ideal, total quotient ring, valuation domain, divided domain, pullback, going-down ring, EGD ring, locally divided ring, weak Baer ring, reduced ring