English
Related papers

Related papers: Proxy smallness meets $t$-structures

200 papers

We give explicit axioms for the algebraic theory of the quasivarieties of right-preordered groups and preordered groups. We then look at lattices of effective equivalence relations, which turn out to be similar to the lattices of…

Category Theory · Mathematics 2026-05-12 Aubril Ony

We introduce a general categorical framework for finiteness conditions that unifies classical notions such as Noetherianness, Artinianness, and various forms of topological compactness. This is achieved through the concept of…

Category Theory · Mathematics 2025-09-15 David Forsman

We introduce a new higher categorical structure called a weakly globular n-fold category. This structure is based on iterated internal categories and on the notion of weak globularity. We identify a suitable class of pseudo-functors whose…

Category Theory · Mathematics 2016-05-24 Simona Paoli

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 of the related section of a line bundle, and their analogues…

Category Theory · Mathematics 2015-07-07 Alexander I. Efimov , Leonid Positselski

We provide an action for gauge theories discretized on simplicial meshes, inspired by finite element methods. The action is discretely gauge invariant and we give a proof of consistency. A discrete Noether's theorem that can be applied to…

Numerical Analysis · Mathematics 2013-06-24 Snorre Harald Christiansen , Tore Gunnar Halvorsen

This work is concerned with approximability (\`{a} la Neeman) and Rouquier dimension for triangulated categories associated to noncommutative algebras over schemes. Amongst other things, we establish that the category of perfect complexes…

Algebraic Geometry · Mathematics 2025-01-08 Timothy De Deyn , Pat Lank , Kabeer Manali Rahul

In the first part, we further advance the study of category theory in a strong balanced factorization category C [Pisani, 2008], a finitely complete category endowed with two reciprocally stable factorization systems such that X \to 1 is in…

Category Theory · Mathematics 2009-04-27 Claudio Pisani

The paper contains general results on the uniqueness of a DG enhancement for triangulated categories. As a consequence we obtain such uniqueness for the unbounded categories of quasi-coherent sheaves, for the triangulated categories of…

Algebraic Geometry · Mathematics 2012-09-18 Valery A. Lunts , Dmitri O. Orlov

Given a positively graded commutative coherent ring A which is finitely generated as an A_0-algebra, a bijection between the tensor Serre subcategories of qgr A and the set of all subsets Y\subseteq Proj A of the form…

Algebraic Geometry · Mathematics 2007-05-23 Grigory Garkusha , Mike Prest

We define the exact category of contraherent cosheaves of contramodules on a locally Noetherian formal scheme, as well as the exact categories of locally contraherent cosheaves of contramodules (with respect to a given open covering). We…

Algebraic Geometry · Mathematics 2026-05-05 Leonid Positselski

We study the spectrum of closed subcategories in a quasi-scheme, i.e. a Grothendieck category $X$. The closed subcategories are the direct analogs of closed subschemes in the commutative case, in the sense that when $X$ is the category of…

Rings and Algebras · Mathematics 2024-11-22 Daniel Rogalski

Extriangulated categories axiomatize extension-closed subcategories of triangulated categories. We show that the homotopy category of an exact quasi-category can be equipped with a natural extriangulated structure.

Category Theory · Mathematics 2020-04-07 Hiroyuki Nakaoka , Yann Palu

Let X be a scheme, and let G be an affine group scheme acting on X. Under reasonable hypotheses on X and G, we construct a t-structure on the derived category of G-equivariant coherent sheaves that in many ways resembles the perverse…

Representation Theory · Mathematics 2009-04-06 Pramod N. Achar

We consider the derived category of permutation modules over a finite group, in positive characteristic. We stratify this tensor triangulated category using Brauer quotients. We describe the set underlying the tt-spectrum of compact…

Representation Theory · Mathematics 2025-07-22 Paul Balmer , Martin Gallauer

It is shown that the Joyal quasi-category model structure for simplicial sets extends to a model structure on simplicial presheaves, for which the weak equivalences are local (or stalkwise) Joyal equivalences.

Category Theory · Mathematics 2016-07-20 Nicholas Meadows

We study some properties of transverse contact structures on small Seifert manifolds, and we apply them to the classification of tight contact structures on a family of small Seifert manifolds.

Geometric Topology · Mathematics 2007-10-10 Paolo Ghiggini

This note presents a uniform treatment of normality and three of its variants---topological, weak and seminormality---for Noetherian schemes. The key is to define these notions for pairs $(Z, X)$ consisting of a (not necessarily reduced)…

Algebraic Geometry · Mathematics 2015-08-10 János Kollár

Let $S$ be a locally Noetherian normal scheme and $\blacklozenge/S$ a set of properties of $S$-schemes. Then we shall write Sch$_{\blacklozenge/S}$ for the full subcategory of the category of $S$-schemes Sch$_{/S}$ determined by the objects…

Algebraic Geometry · Mathematics 2024-01-23 Tomoki Yuji

In this paper, we answer a question of Dwyer, Greenlees, and Iyengar by proving a local ring $R$ is a complete intersection if and only if every complex of $R$-modules with finitely generated homology is proxy small. Moreover, we establish…

Commutative Algebra · Mathematics 2020-09-28 Josh Pollitz

For a tensor triangulated category and any regular cardinal $\alpha$ we study the frame of $\alpha$-localizing tensor ideals and its associated space of points. For a well-generated category and its frame of localizing tensor ideals we…

Category Theory · Mathematics 2022-09-07 Henning Krause , Janina C. Letz