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Related papers: The real cycle class map

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In this paper, we study equivariant real cycle class maps for group actions on real schemes, with a view toward Witt-sheaf characteristic classes. The cycle class maps take values in singular cohomology of the real points of the quotient…

Algebraic Topology · Mathematics 2026-02-25 Lorenzo Mantovani , Ákos K. Matszangosz , Matthias Wendt

We investigate the surjectivity of the real cycle class map from $I$-cohomology to classical intergral cohomology for some real smooth varieties, in particular surfaces. This might be considered as one of several possible incarnations of…

K-Theory and Homology · Mathematics 2024-05-24 Jens Hornbostel

We study the Chow group of zero-cycles of smooth projective varieties over local and strictly local fields. We prove in particular the injectivity of the cycle class map to integral l-adic cohomology for a large class of surfaces with…

Algebraic Geometry · Mathematics 2019-11-21 Hélène Esnault , Olivier Wittenberg

For a quasi-projective smooth scheme X of pure dimension d over a field k and an effective Cartier divisor D on X whose support is a simple normal crossing divisor, we construct a cycle class map from the Chow group of zero-cycles with…

Algebraic Geometry · Mathematics 2022-10-26 Kay Rülling , Shuji Saito

Let $X_\Sigma$ be a smooth, not necessarily compact toric variety. We show that a certain complex, defined in terms of the fan $\Sigma$, computes the integral cohomology of $X_\Sigma$, including the module structure over the homology of the…

Algebraic Topology · Mathematics 2007-10-21 Matthias Franz

We explicitly describe cycle-class maps c_H from motivic cohomology to absolute Hodge cohomology, for smooth quasi-projective and (some) proper singular varieties, and compute special cases of the latter. For smooth projective varieties, we…

Algebraic Geometry · Mathematics 2009-11-11 Matt Kerr , James D. Lewis

Let $\bar{X}$ be a smooth quasi-projective $d$-dimensional variety over a field $k$ and let $D$ be an effective Cartier divisor on it. In this note, we construct cycle class maps from (a variant of) the higher Chow group with modulus of the…

Algebraic Geometry · Mathematics 2018-01-10 Federico Binda

We compute the Chow-Witt rings of split quadrics over a field of characteristic not two. We even determine the full bigraded I-cohomology and Milnor-Witt cohomology rings, including twists by line bundles. The results on I-cohomology…

K-Theory and Homology · Mathematics 2019-09-02 Jens Hornbostel , Heng Xie , Marcus Zibrowius

We describe a natural isomorphism between the set of equivalence classes of pseudocycles and the integral homology groups of a smooth manifold. Our arguments generalize to settings well-suited for applications in enumerative algebraic…

Algebraic Topology · Mathematics 2007-05-23 Aleksey Zinger

We define families of invariants for elements of the mapping class group of S, a compact orientable surface. Fix any characteristic subgroup H of pi_1(S) and restrict to J(H), any subgroup of mapping classes that induce the identity modulo…

Geometric Topology · Mathematics 2015-03-13 Tim D. Cochran , Shelly Harvey , Peter Horn

We describe an explicit morphism of complexes that induces the cycle-class maps from (simplicially described) higher Chow groups to rational Deligne cohomology. The reciprocity laws satisfied by the currents we introduce for this purpose…

Algebraic Geometry · Mathematics 2015-08-06 Jose Ignacio Burgos Gil , Matt Kerr , James D. Lewis , Patrick Lopatto

We introduce the notion of an algebraic cocycle as the algebraic analogue of a map to an Eilenberg-MacLane space. Using these cocycles we develop a ``cohomology theory" for complex algebraic varieties. The theory is bigraded, functorial,…

Algebraic Geometry · Mathematics 2016-09-06 Eric M. Friedlander , H. Blaine Lawson

We show that two natural cycle classes on the moduli space of compact type stable maps to a varying elliptic curve agree. The first is the virtual fundamental class from Gromov-Witten theory, and the second is the Torelli pullback of the…

Algebraic Geometry · Mathematics 2024-09-10 François Greer , Carl Lian

Given a smooth variety $X$ over the field $\mathbb{R}$ of real numbers and a line bundle $\mathcal{L}$ on $X$ with associated topological line bundle $L=\mathcal{L}(\mathbb{R})$, we study the quadratic real cycle class map…

Algebraic Geometry · Mathematics 2026-04-08 Samuel Lerbet

Let $\mathcal{E}(X)$ be the group of homotopy classes of self homotopy equivalences for a connected CW complex $X$. We observe two classes of maps $\mathcal{E}$-maps and co-$\mathcal{E}$-maps. They are defined as the maps $X\to Y$ that…

Algebraic Topology · Mathematics 2016-08-16 Jin-ho Lee , Toshihiro Yamaguchi

This thesis intends to make a contribution to the theories of algebraic cycles and moduli spaces over the real numbers. In the study of the subvarieties of a projective algebraic variety, smooth over the field of real numbers, the cycle…

Algebraic Geometry · Mathematics 2022-11-08 Olivier de Gaay Fortman

We prove that the cyclic chain complex of the categorical coalgebra of singular chains on an arbitrary topological space $X$ is naturally quasi-isomorphic to the $S^1$-equivariant chains of the free loop space of $X$. This statement does…

Algebraic Topology · Mathematics 2024-03-18 Manuel Rivera , Daniel Tolosa

We introduce (co)homology theory for multiple group racks and construct cocycle invariants of compact oriented surfaces in the 3-sphere using their 2-cocycles, where a multiple group rack is a rack consisting of a disjoint union of groups.…

Geometric Topology · Mathematics 2023-10-23 Shosaku Matsuzaki , Tomo Murao

This note is about certain locally complete families of Calabi-Yau varieties constructed by Cynk and Hulek, and certain varieties constructed by Schreieder. We prove that the cycle class map on the Chow ring of powers of these varieties…

Algebraic Geometry · Mathematics 2019-04-19 Robert Laterveer , Charles Vial

We describe explicitly the cohomology of the total complex of certain diagrams of invertible sheaves on normal toric varieties. These diagrams, called wheels, arise in the study of toric singularities associated to dimer models. Our main…

Algebraic Geometry · Mathematics 2019-12-06 Alastair Craw , Alexander Quintero Velez
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