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 …

Ind-coherent sheaves

D Gaitsgory - arXiv preprint arXiv:1105.4857, 2011 - arxiv.org
We develop the theory of ind-coherent sheaves on schemes and stacks. The category of ind-
coherent sheaves is closely related, but inequivalent, to the category of quasi-coherent …

[HTML][HTML] Tensor functors between categories of quasi-coherent sheaves

M Brandenburg, A Chirvasitu - Journal of Algebra, 2014 - Elsevier
For a quasi-compact quasi-separated scheme X and an arbitrary scheme Y we show that the
pullback construction f↦ f⁎ implements an equivalence between the discrete category of …

A cotorsion theory in the homotopy category of flat quasi-coherent sheaves

E Hosseini, S Salarian - Proceedings of the American Mathematical …, 2013 - ams.org
Let $ X $ be a Noetherian scheme, $\mathbf {K}(\operatorname {Flat} X) $ be the homotopy
category of flat quasi-coherent $\mathcal {O} _X $-modules and $\mathbf {K} …

Derived categories of coherent sheaves

A Bondal, D Orlov - arXiv preprint math/0206295, 2002 - arxiv.org
We show how derived categories build bridges across the current mathematical mainstream,
linking geometric and algebraic, commutative and noncommutative, local and global banks …

[图书][B] Semi-infinite algebraic geometry of quasi-coherent sheaves on ind-schemes: Quasi-coherent torsion sheaves, the semiderived category, and the semitensor …

L Positselski - 2023 - books.google.com
Semi-Infinite Geometry is a theory of" doubly infinite-dimensional" geometric or topological
objects. In this book the author explains what should be meant by an algebraic variety of …

Locally finitely presented categories with no flat objects

S Estrada, M Saorin - Forum Mathematicum, 2015 - degruyter.com
If X is a quasi-compact and quasi-separated scheme, the category Qcoh (X) of quasi-
coherent sheaves on X is locally finitely presented. Therefore categorical flat quasi-coherent …

[HTML][HTML] Homotopy-coherent algebra via Segal conditions

H Chu, R Haugseng - Advances in Mathematics, 2021 - Elsevier
Many homotopy-coherent algebraic structures can be described by Segal-type limit
conditions determined by an “algebraic pattern”, by which we mean an∞-category equipped …

A Gabriel theorem for coherent twisted sheaves

A Perego - Mathematische Zeitschrift, 2009 - Springer
The aim of this work is to give a generalization of Gabriel's Theorem on coherent sheaves to
coherent twisted sheaves on noetherian schemes. We start by showing that we can recover …

Relative homological algebra in the category of quasi-coherent sheaves

E Enochs, S Estrada - Advances in Mathematics, 2005 - Elsevier
In this paper, we prove the existence of a flat cover and of a cotorsion envelope for any quasi-
coherent sheaf over a scheme (X, OX). Indeed we prove something more general. We define …