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Building on the concept of a smooth DG algebra we define the notion of a smooth derived category. We the propose the definition of a categorical resolution of singularities. Our main example is the derived category $D(X)$ of quasi-coherent…

Algebraic Geometry · Mathematics 2009-12-03 Valery A. Lunts

For a scheme X, we construct a sheaf C of complexes on X such that for every quasi-compact open subset U of X, C(U) is quasi-isomorphic to the Hochschild complex of the scheme U. Since C is moreover acyclic for taking sections on…

Algebraic Geometry · Mathematics 2007-07-19 Wendy Lowen

Let E be a finite dimensional vector space over an algebraic closure of a finite field with a given linear action of a connected linear algebraic group K and let E' be the dual space. A complex of l-adic sheaves on E is said to be orbital…

Representation Theory · Mathematics 2009-11-19 G. Lusztig

Starting point of the present work is a conjecture of F. Catanese which says that in the derived category of coherent sheaves on any rational homogeneous manifold G/P there should exist a complete strong exceptional poset and a bijection of…

Algebraic Geometry · Mathematics 2007-05-23 Christian Böhning

We present a detailed introduction of the theory of constructible sheaf complexes in the complex algebraic and analytic setting. All concepts are illustrated by many interesting examples and relevant applications, while some important…

Algebraic Geometry · Mathematics 2021-06-03 Laurenţiu G. Maxim , Jörg Schürmann

We develop a version of Hodge theory for a large class of smooth formally proper quotient stacks $X/G$ analogous to Hodge theory for smooth projective schemes. We show that the noncommutative Hodge-de Rham sequence for the category of…

Algebraic Geometry · Mathematics 2022-02-08 Daniel Halpern-Leistner , Daniel Pomerleano

Let C be the stable oo-category of perfect complexes on a derived Deligne-Mumford stack X of finite type over the complex numbers. We prove that the complexified noncommutative topological Chern character is an isomorphism for C. In the…

Algebraic Geometry · Mathematics 2023-08-04 Adeel A. Khan

This work studies conditions under which integral transforms induce exact functors on singularity categories between schemes that are proper over a Noetherian base scheme. A complete characterization for this behavior is provided, which…

Algebraic Geometry · Mathematics 2025-09-16 Uttaran Dutta , Pat Lank , Kabeer Manali Rahul

This article is devoted to studying the ramification of Galois torsors and of $\ell$-adic sheaves in characteristic $p>0$ (with $\ell\not=p$). Let $k$ be a perfect field of characteristic $p>0$, $X$ be a smooth, separated and quasi-compact…

Algebraic Geometry · Mathematics 2011-10-25 Ahmed Abbes , Takeshi Saito

We prove a K\"unneth-type equivalence of derived categories of lisse and constructible Weil sheaves on schemes in characteristic $p > 0$ for various coefficients, including finite discrete rings, algebraic field extensions $E \supset…

Algebraic Geometry · Mathematics 2024-02-21 Tamir Hemo , Timo Richarz , Jakob Scholbach

We define the characteristic cycle of a locally constant \'etale sheaf on a smooth variety in positive characteristic ramified along boundary as a cycle in the cotangent bundle of the variety, at least on a neighborhood of the generic point…

Algebraic Geometry · Mathematics 2020-03-24 Takeshi Saito

A reduced divisor on a nonsingular variety defines the sheaf of logarithmic 1-forms. We introduce a certain coherent sheaf whose double dual coincides with this sheaf. It has some nice properties, for example, the residue exact sequence…

Algebraic Geometry · Mathematics 2007-05-23 Igor V. Dolgachev

We construct an abelian category A(G) of sheaves over a category of closed subgroups of the r-torus G and show it is of finite injective dimension. It can be used as a model for rational $G$-spectra in the sense that there is a homology…

Algebraic Topology · Mathematics 2007-05-23 J. P. C. Greenlees

We introduce the notion of integrable connections for a sheaf of differential graded algebras on a topological space. We then describe them in the finite locally projective setting, when the sheaf is either the de Rham complex of a formal…

Algebraic Geometry · Mathematics 2025-02-05 Rubén Muñoz--Bertrand

In this paper we associate to t-motives with level structures a finite dimensional vector subspace (subspace of uniformizers). We study the particular case of elliptic sheaves finding some relations with some objects from conformal field…

Algebraic Geometry · Mathematics 2007-05-23 Arturo Alvarez

Let $\mathcal C$ be closed symmetric monoidal Grothendieck category. We define the pure derived category with respect to the monoidal structure via a relative injective model category structure on the category $\mathbf{C}(\mathcal C)$ of…

Category Theory · Mathematics 2014-08-14 Sergio Estrada , James Gillespie , Sinem Odabaşi

We prove the following result of Bondal's: that there is a fully faithful embedding $\kappa$ of the perfect derived category of a proper toric variety into the derived category of constructible sheaves on a compact torus. We compare this…

Algebraic Geometry · Mathematics 2010-07-01 David Treumann

We study non-commutative projective lines over not necessarily algebraic bimodules. In particular, we give a complete description of their categories of coherent sheaves and show they are derived equivalent to certain bimodule species. This…

Representation Theory · Mathematics 2015-10-16 D. Chan , A. Nyman

We classify the unipotent character sheaves on a fixed connected component of a reductive algebraic group under a mild hypothesis on the characteristic of the ground field.

Representation Theory · Mathematics 2008-07-17 G. Lusztig

Let $f \colon X \to Y$ be a morphism of concentrated schemes. We characterize $f$-perfect complexes $\mathcal{E}$ as those such that the functor $\mathcal{E} \otimes^{\mathbf{L}}_X \mathbf{L} f^*-$ preserves bounded complexes. We prove, as…

Algebraic Geometry · Mathematics 2023-09-15 Leovigildo Alonso , Ana Jeremias , Fernando Sancho
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