Publication at Faculty of Mathematics and Physics |
2023
Abstract
Let (A,E) be an exact category. We establish basic results that allow one to identify sub(bi)functors of Ext(epsilon)(-,-) using additivity of numericalfunctions and restriction to subcategories.
We also study a small number ofthese new functors over commutative local rings in detail and find a range ofapplications from detecting regularity to understanding Ulrich modules.