131 citations · 953 across the 64 of their papers we have counts for
6 papers · 1 filter
Tensor-Hom formalism for modules over nonunital rings
Leonid Positselski
We say that a ring is t-unital if the natural map is an isomorphism, and a left -module is c-unital if the natural map $P\rightarrow\operatorn…
Comodules and contramodules over coalgebras associated with locally finite categories
Leonid Positselski
We explain how to attach a coalgebra over a field to a small -linear category satisfying suitable finiteness conditions. In this context, we study f…
Flat comodules and contramodules as directed colimits, and cotorsion periodicity
Leonid Positselski
This paper is a follow-up to arXiv:2212.09639. We consider two algebraic settings of comodules over a coring and contramodules over a topological ring with a countable base of two-…
A bounded below, noncontractible, acyclic complex of projective modules
Leonid Positselski
We construct examples of bounded below, noncontractible, acyclic complexes of finitely generated projective modules over some rings , as well as bounded above, noncontractible,…
Homological full-and-faithfulness of comodule inclusion and contramodule forgetful functors
Leonid Positselski
In this paper we consider a conilpotent coalgebra over a field . Let be the natural functor of inclusion of the ca…
Generalized periodicity theorems
Leonid Positselski
Let be a ring and be a class of strongly finitely presented (FP) -modules closed under extensions, direct summands, and syzygies. Let $(\mathsf A,\mat…