73 citations · 386 across the 43 of their papers we have counts for
4 papers · 2 filters
A characterization of central extensions relative to n-nilpotent objects
Marino Gran, James R. A. Gray
We characterize the central extensions, in the sense of the categorical theory of central extensions of Janelidze and Kelly, relative to the Birkhoff subcategory of -nilpotent o…
Quasi-pointed exactness and torsion
Marino Gran, George Janelidze
We show that, under some mild assumptions, every quasi-pointed category C carries a canonical near-torsion theory (T,F), where T consists of the 0-supported objects, that is, those…
A new characterization of arithmetical categories and Pixley's theorem
Marino Gran
We characterize the arithmetical categories - the exact Mal'tsev categories whose lattices of congruences are distributive - by a simple condition on some suitable pushouts and a f…
Torsion and exactness
Marino Gran, George Janelidze
We give an equivalent definition of a non-pointed torsion theory, also called a pretorsion theory in the literature. This uses a new, more general, notion of a near-torsion theory,…