UPPER BOUNDS FOR FINITENESS OF GENERALIZED LOCAL COHOMOLOGY MODULES

Abstract

Let R be a commutative Noetherian ring with non-zero identity and a an ideal of R. Let M be a nite R{module of nite projective dimension and N an arbitrary nite R{module. We characterize the membership of the generalized local cohomology modules H i (M;N) in certain Serre subcategories of the category of modules from upper bounds. We dene and study the properties of a generalization of cohomological dimension of generalized local cohomology modules. Let S be a Serre subcategory of the category of R{modules and n > pdM be an integer such that H i(M;N) belongs to S for all i > n. Then, for any ideal ba, it is also shown that the module H n (M;N)=bH n (M;N) belongs to S.