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Related papers: Variations on the Bloch-Ogus Theorem

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In this note we relate three topics for arithmetic schemes: a general duality for \'etale constructible torsion sheaves, an \'etale homology theory, and a Gersten-Bloch-Ogus-Kato complex. The results in this paper have been used in other…

Algebraic Geometry · Mathematics 2012-03-13 Uwe Jannsen , Shuji Saito , Kanetomo Sato

We prove a version of Quillen's stratification theorem in equivariant homotopy theory for a finite group $G$, generalizing the classical theorem in two directions. Firstly, we work with arbitrary commutative equivariant ring spectra as…

Algebraic Topology · Mathematics 2024-11-26 Tobias Barthel , Natalia Castellana , Drew Heard , Niko Naumann , Luca Pol

We prove the existence of a sequence of commutative diagrams generalizing existing results on the cohomology of the Borel-Serre boundary and well-rounded retract to the context of the well-tempered complex. Our main theorem provides a…

Number Theory · Mathematics 2025-10-21 Dylan Galt , Mark McConnell

We introduce a notion of proper morphism for schematic finite spaces and prove the analogue of Grothendieck's finiteness theorem for it by means of the classic result for schemes and general descent arguments. This result also generalizes…

Algebraic Geometry · Mathematics 2023-05-22 Javier Sánchez González

We show that the logarithmic version of the syntomic cohomology of Fontaine and Messing for semistable varieties over $p$-adic rings extends uniquely to a cohomology theory for varieties over $p$-adic fields that satisfies $h$-descent. This…

Number Theory · Mathematics 2016-10-19 Jan Nekovář , Wiesława Nizioł

Let $X$ be a smooth proper variety over a field $k$ and suppose that the degree map $\mathrm{CH}_0(X \otimes_k K) \to \mathbb{Z}$ is isomorphic for any field extension $K/k$. We show that $G(\mathrm{Spec} k) \to G(X)$ is an isomorphism for…

Algebraic Geometry · Mathematics 2021-09-09 Wataru Kai , Shusuke Otabe , Takao Yamazaki

Let $k$ be a perfect field of characteristic $p > 0$, $W_n = W_n(k)$. For separated $k$-schemes of finite type, we explain how rigid cohomology with compact supports can be computed as the cohomology of certain de Rham-Witt complexes with…

Algebraic Geometry · Mathematics 2012-05-22 Pierre Berthelot

We know that semi-regular sub-varieties satisfy the variational Hodge conjecture i.e., given a family of smooth projective varieties $\pi:\mathcal{X} \to B$, a special fiber $\mathcal{X}_o$ and a semi-regular subvariety $Z \subset…

Algebraic Geometry · Mathematics 2016-12-05 Ananyo Dan , Inder Kaur

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

In this paper, given a smooth proper scheme X over a p-adic dvr and a p-power torsion etale local system L on it, we study a family of sheaves associated to the cohomology of local relative (Phi-Gamma)-modules of L and their cohomology. As…

Number Theory · Mathematics 2007-05-23 Fabrizio Andreatta , Adrian Iovita

We prove several duality theorems for the Galois and etale cohomology of 1-motives defined over local and global fields and establish a 12-term Poitou-Tate type exact sequence. The results give a common generalisation and sharpening of…

Number Theory · Mathematics 2007-05-23 David Harari , Tamas Szamuely

Let $k$ be a field, with absolute Galois group $\Gamma$. Let $A/k$ be a finite \'etale group scheme of multiplicative type, i.e. a discrete $\Gamma$-module. Let $n \geq 2$ be an integer, and let $x \in H^n(k,A)$ be a cohomology class. We…

Algebraic Geometry · Mathematics 2018-03-30 Cyril Demarche , Mathieu Florence

We prove an effective stabilization result for the sheaf cohomology groups of line bundles on flag varieties parametrizing complete flags in k^n, as well as for the sheaf cohomology groups of polynomial functors applied to the cotangent…

Algebraic Geometry · Mathematics 2026-02-10 Claudiu Raicu , Keller VandeBogert

We present a simple proof of a precise version of the localization theorem in equivariant cohomology. As an application, we describe the cohomology algebra of any compact symplectic variety with a multiplicity-free action of a compact Lie…

dg-ga · Mathematics 2007-05-23 Michel Brion , Michèle Vergne

We show that the operadic cohomology for any type of algebras over a non-symmetric operad A can be computed as Ext in the category of operadic A-modules. We use this principle to prove that the Gerstenhaber-Schack diagram cohomology is…

Algebraic Topology · Mathematics 2013-12-20 Martin Doubek

We prove various finiteness and representability results for cohomology of finite flat abelian group schemes. In particular, we show that if $f\colon X\rightarrow \mathrm{Spec}(k)$ is a projective scheme over a field $k$ and $G$ is a finite…

Algebraic Geometry · Mathematics 2025-04-10 Daniel Bragg , Martin Olsson

We extend the notion of absolute subsets of Betti moduli spaces of smooth algebraic varieties to the case of normal varieties. As a consequence we prove that twisted cohomology jump loci in rank one over a normal variety are a finite union…

Algebraic Geometry · Mathematics 2022-02-15 Leonardo A. Lerer

We give an explicit formula for the zeroth $\mathbb{A}^1$-homology sheaf of a smooth proper variety. We also provide a simple proof of a theorem of Kahn-Sujatha which describes hom sets in the birational localization of the category of…

Algebraic Geometry · Mathematics 2022-05-26 Junnosuke Koizumi

We would like to construct a new Grothendieck topology for arithmetic schemes, whose cohomology groups associated with motivic complexes of sheaves are finitely generated and whose Euler characteristics are related to special values of…

Number Theory · Mathematics 2007-05-23 Stephen Lichtenbaum

We establish a Grothendieck--Lefschetz theorem for smooth ample subvarieties of smooth projective varieties over an algebraically closed field of characteristic zero and, more generally, for smooth subvarieties whose complement has small…

Algebraic Geometry · Mathematics 2023-02-07 Tommaso de Fernex , Chung Ching Lau
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