Reduced and coreduced modules with respect to inverse families of ideals

Abstract

Let $R$ be a commutative ring and $\Phi$ an inverse family of ideals with greatest proper member $\mathcal{L}$. We introduce and study $\Phi$-reduced and $\Phi$-coreduced modules, extending the corresponding notions for powers of a single ideal. We show that, on these classes of modules, the generalized torsion and completion functors associated with $\Phi$ are determined by $\mathcal{L}$. We establish characterizations and closure properties of these modules and obtain a Greenlees-May type adjunction and a Matlis-Greenlees-May type characterization. When $\Phi$ is a system of ideals, we further investigate the radicality of the generalized torsion functor and derive associated torsion theories on suitable Serre subcategories. These results provide a module-theoretic framework for studying generalized torsion and completion with respect to families of ideals.