Coherent analogues of matrix factorizations and relative singularity categories

AI Efimov, L Positselski - Algebra & Number Theory, 2015 - msp.org
We define the triangulated category of relative singularities of a closed subscheme in a
scheme. When the closed subscheme is a Cartier divisor, we consider matrix factorizations …

The tilting–cotilting correspondence

L Positselski, J Šťovíček - International Mathematics Research …, 2021 - academic.oup.com
To a big-tilting object in a complete, cocomplete abelian category with an injective
cogenerator we assign a big-cotilting object in a complete, cocomplete abelian category with …

Flat quasi-coherent sheaves as direct limits, and quasi-coherent cotorsion periodicity

L Positselski, J Stovicek - arXiv preprint arXiv:2212.09639, 2022 - arxiv.org
We show that every flat quasi-coherent sheaf on a quasi-compact quasi-separated scheme
is a directed colimit of locally countably presentable flat quasi-coherent sheaves. More …

Derived Knörrer periodicity and Orlov's theorem for gauged Landau–Ginzburg models

Y Hirano - Compositio Mathematica, 2017 - cambridge.org
We prove a Knörrer-periodicity-type equivalence between derived factorization categories of
gauged Landau–Ginzburg models, which is an analogy of a theorem proved by Shipman …

Homotopy finiteness of some DG categories from algebraic geometry

AI Efimov - Journal of the European Mathematical Society, 2020 - ems.press
In this paper, we prove that the bounded derived category Db coh (Y) of coherent sheaves
on a separated scheme Y of finite type over a field k of characteristic zero is homotopically …

Weakly curved A-infinity algebras over a topological local ring

L Positselski - arXiv preprint arXiv:1202.2697, 2012 - arxiv.org
We define and study the derived categories of the first kind for curved DG and A-infinity
algebras complete over a pro-Artinian local ring with the curvature elements divisible by the …

[HTML][HTML] Covers, envelopes, and cotorsion theories in locally presentable abelian categories and contramodule categories

L Positselski, J Rosický - Journal of Algebra, 2017 - Elsevier
We prove general results about completeness of cotorsion theories and existence of covers
and envelopes in locally presentable abelian categories, extending the well-established …

Contramodules

L Positselski - Confluentes Mathematici, 2021 - numdam.org
Contramodules are module-like algebraic structures endowed with infinite summation (or,
occasionally, integration) operations satisfying natural axioms. Introduced originally by …

Exact DG-categories and fully faithful triangulated inclusion functors

L Positselski - arXiv preprint arXiv:2110.08237, 2021 - arxiv.org
We construct an" almost involution" assigning a new DG-category to a given one, and use
this construction in order to recover, say, the abelian category of graded modules over the …

Triangulated Matlis equivalence

L Positselski - Journal of Algebra and Its Applications, 2018 - World Scientific
This paper is a sequel to [L. Positselski, Dedualizing complexes and MGM duality, J. Pure
Appl. Algebra 220 (12)(2016) 3866–3909, arXiv: 1503.05523 [math. CT]; Contraadjusted …