131 citations · 953 across the 64 of their papers we have counts for
13 papers · 1 filter
Contraderived categories of CDG-modules
Leonid Positselski, Jan Stovicek
For any CDG-ring , we show that the homotopy category of graded-projective (left) CDG-modules over is equivalent to the quotient category of the ho…
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…
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…
Topologically semiperfect topological rings
Leonid Positselski, Jan Stovicek
We define topologically semiperfect (complete, separated, right linear) topological rings and characterize them by equivalent conditions. We show that the endomorphism ring of a mo…
Closure properties of
Leonid Positselski, Pavel Prihoda, Jan Trlifaj
Let be a class of modules and the class of all direct limits of modules from . The class is well understo…
An explicit self-dual construction of complete cotorsion pairs in the relative context
Leonid Positselski
Let be a homomorphism of associative rings, and let be a hereditary complete cotorsion pair in . Let $(\mathcal F_A,\mathcal C_A)…
Projective covers of flat contramodules
Silvana Bazzoni, Leonid Positselski, Jan Stovicek
We show that a direct limit of projective contramodules (over a right linear topological ring) is projective if it has a projective cover. A similar result is obtained for …
Matlis category equivalences for a ring epimorphism
Silvana Bazzoni, Leonid Positselski
Under mild assumptions, we construct the two Matlis additive category equivalences for an associative ring epimorphism . Assuming that the ring epimorphism is homol…
Flat ring epimorphisms of countable type
Leonid Positselski
Let be an associative ring epimorphism such that is a flat left -module. Assume that the related Gabriel topology of right ideals in has a countable…
Nonhomogeneous quadratic duality and curvature
Leonid Positselski
This is a slightly corrected version of the article published by Functional Analysis and its Applications in 1993. We define the quadratic duality for algebras with nonhomogeneous…