English
Related papers

Related papers: A lifting functor for toric sheaves

200 papers

Let $X$ and $Y$ be real analytic manifolds and let $\Lambda \subseteq T^*X$ and $\Sigma \subseteq T^*Y$ be closed conic subanalytic singular isotropics. Given a sheaf $K \in \mathrm{Sh}_{-\Lambda \times \Sigma}(X \times Y)$ microsupported…

Algebraic Topology · Mathematics 2025-11-05 Yuxuan Hu

We prove an unstraightening result for lax transformations between functors from an arbitrary $(\infty,2)$-category to that of $(\infty,2)$-categories. We apply this to study partially (op)lax and weighted (co)limits, giving fibrational…

Category Theory · Mathematics 2024-04-08 Fernando Abellán , Andrea Gagna , Rune Haugseng

In a previous paper we introduced the concept of semiseparable functor. Here we continue our study of these functors in connection with idempotent (Cauchy) completion. To this aim, we introduce and investigate the notions of (co)reflection…

Category Theory · Mathematics 2023-06-13 Alessandro Ardizzoni , Lucrezia Bottegoni

This paper investigates the interplay between properties of a topological space $X$, in particular of its natural order, and properties of the lax comma category $\mathsf{Top} \Downarrow X$, where $\mathsf{Top}$ denotes the category of…

Category Theory · Mathematics 2025-12-09 Maria Manuel Clementino , Dirk Hofmann , Rui Prezado

Let X be a smooth proper variety over the quotient field of a Henselian discrete valuation ring with algebraically closed residue field of characteristic p. We show that for any coherent sheaf E on X, the index of X divides the…

Algebraic Geometry · Mathematics 2016-03-29 Hélène Esnault , Marc Levine , Olivier Wittenberg

In this paper, we extend the structure theorem for smooth projective varieties with nef tangent bundle to projective klt varieties whose tangent sheaf is either positively curved or almost nef. Specifically, we show that such a variety $X$,…

Algebraic Geometry · Mathematics 2025-07-23 Masataka Iwai , Shin-ichi Matsumura , Guolei Zhong

Let X be e quasi-compact and semi-separated scheme. If every at quasi- coherent sheaf has finite cotorsion dimension, we prove that X is n-perfect for some n > 0. If X is coherent and n-perfect(not necessarily of finite krull dimension), we…

Algebraic Geometry · Mathematics 2013-12-04 Esmaeil Hosseini

We define a new perverse t-exact pullback operation on derived categories of constructible sheaves which generalizes most perverse t-exact functors in sheaf theory, such as microlocalization, the Fourier-Sato transform and vanishing cycles.…

Algebraic Geometry · Mathematics 2025-10-21 Adeel A. Khan , Tasuki Kinjo , Hyeonjun Park , Pavel Safronov

We give sufficient conditions which ensure that a functor of finite length from an additive category to finite-dimensional vector spaces has a projective resolution whose terms are finitely generated. For polynomial functors, we study also…

K-Theory and Homology · Mathematics 2023-07-14 Aurélien Djament , Antoine Touzé

We give a definition of Cox rings and Cox sheaves for varieties over nonclosed fields that is compatible with torsors under quasitori, including universal torsors. We study their existence and classification, we make the relation to torsors…

Algebraic Geometry · Mathematics 2018-09-26 Ulrich Derenthal , Marta Pieropan

Suppose we are given complex manifolds $X$ and $Y$ together with substacks $\mathcal{S}$ and $\mathcal{S}'$ of modules over algebras of formal deformation $\mathcal{A}$ on $X$ and $\mathcal{A}'$ on $Y$, respectively. Suppose also we are…

Algebraic Geometry · Mathematics 2013-01-10 Ana Rita Martins , Teresa Monteiro Fernandes , David Raimundo

We prove that the coherent Springer sheaf and its parabolic analogues are concentrated in cohomological degree $0$, as predicted by Ben-Zvi-Chen-Helm-Nadler, Zhu, Emerton-Gee-Hellmann, Hansen, and others. More generally, we show that the…

Representation Theory · Mathematics 2026-02-23 Oron Y. Propp

Let X be a smooth toric variety stratified by the torus action. This paper is a presentation of a description of the category Perv_X of perverse sheaves on X relatively to the fixed stratification. We define a category of representations of…

Algebraic Geometry · Mathematics 2010-03-17 Delphine Dupont

In this paper we show that it is possible to define a topology on the category of formal schemes over a ring of $p$-adic integers such that the left adjoint of the Greenberg Transform is a site cocontinuous functor when we equip the…

Algebraic Geometry · Mathematics 2019-10-02 Geoff Vooys

We generalize the adjunction between the functors $Rf_*$ and $f^!$ of derived categories of quasi-coherent sheaves for proper morphisms $f\colon X \to Y$ of Noetherian schemes to the following situation: Let $f$ be a finite type morphism…

Algebraic Geometry · Mathematics 2018-10-16 Tobias Schedlmeier

We study sheaves in the context of a duality theory for lattice structure endowed with extra operations, and in the context of forcing in a topos. Using Sheaf duality theory of Comer for cylindric algebras, we give a representation theorem…

Logic · Mathematics 2018-11-06 Trek Sayed Ahmed

In this paper, we investigate the properties of $A$-coherent and $A$-quasi-coherent sheaves within the framework of algebraic geometry over non-algebraically closed fields. We define an $\mathcal{O}_X$-module to be $A$-coherent (resp.…

Algebraic Geometry · Mathematics 2026-04-20 Hamet Seydi , Teylama Miabey

Let K be a comonad on a model category M. We provide conditions under which the associated category of K-coalgebras admits a model category structure such that the forgetful functor to M creates both cofibrations and weak equivalences. We…

Algebraic Topology · Mathematics 2014-02-26 Kathryn Hess , Brooke Shipley

Let $X$ be a scheme, proper over a commutative noetherian ring $A$. We introduce the concept of an ample filter of invertible sheaves on $X$ and generalize the most important equivalent criteria for ampleness of an invertible sheaf. We also…

Algebraic Geometry · Mathematics 2018-06-05 Dennis S. Keeler

Let $(\mathcal{C},\mathbb{E},\mathfrak{s})$ be an extriangulated category with a proper class $\xi$ of $\mathbb{E}$-triangles. In this paper, we study Gorenstein derived functors for extriangulated categories. More precisely, we first…

Category Theory · Mathematics 2021-05-07 Zhenggang He