A Generalization of Divided Domains and Its Connection to Weak Baer Going-Down Rings

Abstract

Many results on going-down domains and divided domains are generalized to the context of rings with von Neumann regular total quotient rings. A (commutative unital) ring R is called regular divided if each P ∈ Spec(R)∖(Max(R) ∩ Min(R)) is comparable with each principal regular ideal of R. Among rings having von Neumann regular total quotient rings, the regular divided rings are the pullbacks K× K/P D where K is von Neumann regular, P ∈ Spec(K) and D is a divided domain. Any regular divided ring (for instance, regular comparable ring) with a von Neumann regular total quotient ring is a weak Baer going-down ring. If R is a weak Baer going-down ring and T is an extension ring with a von Neumann regular total quotient ring such that no regular element of R becomes a zero-divisor in T, then R ⊆ T satisfies going-down. If R is a weak Baer ring and P ∈ Spec(R), then R + PR (P) is a going-down ring if and only if R/P and R P are going-down rings. The weak Baer going-down rings R such that Spec(R)∖Min(R) has a unique maximal element are characterized in terms of the existence of suitable regular divided overrings.