Anneaux de polynômes sur un anneau de Mori
Let be an ideal of Noetherian local ring and a finitely generated -module of dimension . In this paper we investigate the Artinianness of formal local cohomology modules under certain conditions on the local cohomology modules with respect to . Also we prove that for an arbitrary local ring (not necessarily complete), we have
Let be a set of ideals of a commutative Noetherian ring . We use the notion of -closure operation which is a semiprime closure operation on submodules of modules to introduce the class of -Laskerian modules. This enables us to investigate the set of associated prime ideals of certain -closed submodules of local cohomology modules.
We establish several finiteness characterizations and equations for the cardinality and the length of the set of overrings of rings with nontrivial zero divisors and integrally closed in their total ring of fractions. Similar properties are also obtained for related extensions of commutative rings that are not necessarily integral domains. Numerical characterizations are obtained for rings with some finiteness conditions afterwards.
Let be a complete local ring, an ideal of and and two Matlis reflexive -modules with . We prove that if is a finitely generated -module, then is Matlis reflexive for all and in the following cases: (a) ; (b) ; where is the cohomological dimension of in ; (c) . In these cases we also prove that the Bass numbers of are finite.
We prove that for a commutative ring , every noetherian (artinian) -module is quasi-injective if and only if every noetherian (artinian) -module is quasi-projective if and only if the class of noetherian (artinian) -modules is socle-fine if and only if the class of noetherian (artinian) -modules is radical-fine if and only if every maximal ideal of is idempotent.