On Ext and Hyperext groups in the category of functors
Let R be a commutative noetherian ring with unit and let f denote the category of functors from the category of finitely generated R-modules to R-modules. Let I in f denote the inclusion functor. We study homological algebra of I in the category f (Ext-groups) and its generalization when we allow coefficients to be chain complexes in f (Hyperext-groups). We compare the Ext-groups of I with coefficients in arbitrary F in f with Ext-groups of I with coefficients in stable derived functors of F. The latter groups are relatively easily calculable because the stable derived functors are linear. On the other hand, known calculations of Ext-groups of I with coefficients in F can shed light on the stable derived functors of F which are hard to approach.
Authors
- Stanisław Betley (ORCID: https://orcid.org/0000-0003-3688-3370)
Institutions
- Institute of Mathematics (PL)
- University of Warsaw (PL)
Publication Details
- Journal
- Gulf Journal of Mathematics
- Published
- 2025-08-18
- DOI
- https://doi.org/10.56947/gjom.v20i2.3211
- Primary Topic
- Homotopy and Cohomology in Algebraic Topology
- Type
- article
- Field-Weighted Citation Impact
- 0.00