Weak multiplication modules
In this paper we characterize weak multiplication modules.
Weak multiplication modules over a pullback of Dedekind domains
Let R be the pullback, in the sense of Levy [J. Algebra 71 (1981)], of two local Dedekind domains. We classify all those indecomposable weak multiplication R-modules M with finite-dimensional top, that is, such that M/Rad(R)M is finite-dimensional over R/Rad(R). We also establish a connection between the weak multiplication modules and the pure-injective modules over such domains.
Wenn B ein Hauptidealring ist, so sind alle projektiven B [X, Y]-Moduln frei.
When is each proper overring of R an S(Eidenberg)-domain?
A domain R is called a maximal "non-S" subring of a field L if R ⊂ L, R is not an S-domain and each domain T such that R ⊂ T ⊆ L is an S-domain. We show that maximal "non-S" subrings R of a field L are the integrally closed pseudo-valuation domains satisfying dim(R) = 1, dimv(R) = 2 and L = qf(R).
When is every order ideal a ring ideal?
A lattice-ordered ring is called an OIRI-ring if each of its order ideals is a ring ideal. Generalizing earlier work of Basly and Triki, OIRI-rings are characterized as those -rings such that is contained in an -ring with an identity element that is a strong order unit for some nil -ideal of . In particular, if denotes the set of nilpotent elements of the -ring , then is an OIRI-ring if and only if is contained in an -ring with an identity element that is a strong order unit....
Whitehead Modules over Domains.