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Related papers: Coniveau filtrations with Z/2 coefficients

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The Z_2-graded Cech cohomology theory is considered in the framework of noncommutative geometry over complex number field and in particular the homotopy invariance and Morita invariance are proven.

K-Theory and Homology · Mathematics 2007-05-23 Do Ngoc Diep

We associate to each real algebraic variety a filtered chain complex, the weight complex, which is well-defined up to filtered quasi-isomorphism, and which induces on classical (compactly supported) homology with Z/2 coefficients an analog…

Algebraic Geometry · Mathematics 2017-01-16 Clint McCrory , Adam Parusinski

The present paper describes a relation between the quotient of the fundamental group of a smooth quasi-projective variety by its second commutator and the existence of maps to orbifold curves. It extends previously studied cases when the…

Algebraic Geometry · Mathematics 2018-05-04 E. Artal Bartolo , J. I. Cogolludo-Agustin , A. Libgober

We study the Hodge filtration on the local cohomology sheaves of a smooth complex algebraic variety along a closed subscheme Z in terms of log resolutions, and derive applications regarding the local cohomological dimension, the Du Bois…

Algebraic Geometry · Mathematics 2022-08-23 Mircea Mustata , Mihnea Popa

For a coherent filtered D-module we show that the dual of each graded piece over the structure sheaf is isomorphic to a certain graded piece of the ring-theoretic local cohomology complex of the graded quotient of the dual of the filtered…

Algebraic Geometry · Mathematics 2014-07-02 Morihiko Saito , Christian Schnell

We investigate when two generalized real Bott manifolds of height 2 have isomorphic cohomology rings with Z/2 coefficients and also when they are diffeomorphic. It turns out that cohomology rings with Z/2 coefficients do not distinguish…

Algebraic Topology · Mathematics 2010-05-02 Mikiya Masuda

Let $C$ be a complex integral curve with plannar singularities. Let $J$ be the compactified Jacobian of $C$. There are two filtrations on the cohomology group $H^*(J)$. One is obtained by the nilpotent morphism defined by cupping a certain…

Algebraic Geometry · Mathematics 2026-03-10 Yao Yuan

We introduce the motivic coniveau exact couple of a smooth scheme, in the framework of mixed motives, whose property is to universally give rise to coniveau spectral sequences through realizations. The main result is a computation of its…

Algebraic Geometry · Mathematics 2011-06-07 F. Déglise

This paper studies the homotopy-type of bi-filtrations of compact manifolds induced as the pre-image of filtrations of the plane for generic smooth functions f : M --> R^2. The primary goal of the paper is to allow for a simple description…

Algebraic Topology · Mathematics 2023-09-13 Ryan Budney , Tomasz Kaczynski

In this note, we consider unramified cohomology with $\mathbb{Z}/2$ coefficients for some (degree two) quotient varieties and describe a method that allows one to prove the non-vanishing of these groups under certain conditions. We apply…

Algebraic Geometry · Mathematics 2019-09-05 Humberto A. Diaz

Given a morphism between complex projective varieties, we make several conjectures on the relations between the set of pseudo-effective (co)homology classes which are annihilated by pushforward and the set of classes of varieties contracted…

Algebraic Geometry · Mathematics 2013-03-04 O. Debarre , Z. Jiang , C. Voisin

Using log convergent topoi, %In the derived category of filtered complexes of %sheaves of modules over %an isostructure we define two fundamental filtered complexes $(E_{conv},P)$ and $(C_{conv},P)$ for the log scheme obtained by a smooth…

Algebraic Geometry · Mathematics 2025-10-08 Yukiyoshi Nakkajima , Atsushi Shiho

We describe the weight filtration in the cohomology of toric varieties. We present a role of the Frobenius automorphism in an elementary way. We prove that equivariant intersection homology of an arbitrary toric variety is pure. We obtain…

Algebraic Geometry · Mathematics 2007-05-23 Andrzej Weber

Let F denote a field of characteristic different from two. In this paper we describe the mod 2 cohomology of a Galois group which is determined by the Witt ring WF.

Algebraic Topology · Mathematics 2016-09-07 Alejandro Adem , Dikran Karagueuzian , Jan Minac

In this paper we study mixed Hodge structures on the cohomology of locally symmetric varieties and give an application to modular forms. After proving vanishing of some Hodge numbers, we focus on the weight filtration on the last Hodge…

Algebraic Geometry · Mathematics 2024-08-13 Shouhei Ma

We extend results of Colliot-Th\'el\`ene and Raskind on the $\mathcal{K}_2$-cohomology of smooth projective varieties over a separably closed field $k$ to the \'etale motivic cohomology of smooth, not necessarily projective, varieties over…

Algebraic Geometry · Mathematics 2019-11-22 Bruno Kahn

In this paper, we give an explicit description about the second Hochschild cohomology groups of bipartite Brauer graph algebras with trivial grading. Based on this, we provide geometric interpretations of deformations associated to some…

Rings and Algebras · Mathematics 2026-04-27 Yuming Liu , Zhengfang Wang , Bohan Xing

We compute the sheaf cohomology with constant $\mathbb{Z}_2$ coefficients of a concrete class of locally profinite sets of independent interest. We introduce $k$-sheer partitions to aid in constructions. It is also shown that questions of…

Logic · Mathematics 2026-04-14 Mark Schachner

We study the relation between the Hodge filtration of the de Rham cohomology of a proper smooth supervariety $X$ and the usual Hodge filtration of the corresponding reduced variety $X_0$.

Algebraic Geometry · Mathematics 2023-08-17 Alexander Polishchuk , Dmitry Vaintrob

We prove the K\"unneth formula for the irregular Hodge filtrations on the exponentially twisted de Rham and the Higgs cohomologies of smooth quasi-projective complex varieties. The method involves a careful comparison of the underlying…

Algebraic Geometry · Mathematics 2018-06-13 Kai-Chieh Chen , Jeng-Daw Yu