Orateur
Alberto Facchini
(Università di Padova)
Description
We will present a notion of (pre)torsion theory in general categories and two interesting examples of such pretorsion theories. Torsion theories in arbitrary categories have been studied by Grandis, Janelidze, Márki and several others. Our main examples will be in the category of preordered sets and the category of finite algebras with one operation, unary, and no axioms (i.e., the category of all mappings $f\colon X\to X$, where $X$ is a finite set). Our results appear in joint papers with Carmelo Antonio Finocchiaro, Marino Gran and Leila Heidari Zadeh.
