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Related papers: Kummer varieties and their Brauer groups

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We discuss logical links among uniformity conjectures concerning K3 surfaces and abelian varieties of bounded dimension defined over number fields of bounded degree. The conjectures concern the endomorphism algebra of an abelian variety,…

Number Theory · Mathematics 2021-12-14 Martin Orr , Alexei N. Skorobogatov , Yuri G. Zarhin

We study a new object that can be attached to an abelian variety or a complex torus: the invariant Brauer group, as recently defined by Yang Cao. Over the field of complex numbers this is an elementary abelian 2-group with an explicit upper…

Algebraic Geometry · Mathematics 2021-06-01 Martin Orr , Alexei N. Skorobogatov , Domenico Valloni , Yuri G. Zarhin

For a prime $p$, we study subgroups of order p of the Brauer group Br(S) of a general complex polarized K3 surface of degree 2d, generalizing earlier work of van Geemen. These groups correspond to sublattices of index p of the…

Algebraic Geometry · Mathematics 2021-12-28 Kelly McKinnie , Justin Sawon , Sho Tanimoto , Anthony Várilly-Alvarado

We prove that the quotient of the Brauer group of a product of varieties over k by the sum of the images of the Brauer groups of factors has finite exponent. The bulk of the proof concerns p-primary torsion in characteristic p. Our approach…

Algebraic Geometry · Mathematics 2025-10-03 Alexei N. Skorobogatov

The Tate conjecture for divisors on varieties over number fields is equivalent to finiteness of $\ell$-primary torsion in the Brauer group. We show that this finiteness is actually uniform in one-dimensional families for varieties that…

Algebraic Geometry · Mathematics 2018-01-24 Anna Cadoret , François Charles

This article focuses on smooth, projective, and geometrically integral varieties $X$ defined over a number field $k$ with torsion-free geometric Picard groups. We establish an isomorphism between the Brauer groups of $X$ and its symmetric…

Algebraic Geometry · Mathematics 2026-04-23 Yongqi Liang , Xingyu Liu , Hui Zhang

We prove that every element of order 2 in the Brauer group of a complex Kummer surface X descends to an Enriques quotient of X. In 'generic' cases this gives a bijection between the set Enr(X) of Enriques quotients of X up to isomorphism…

Algebraic Geometry · Mathematics 2022-02-17 Alexei N. Skorobogatov , Domenico Valloni

Let $k$ be a number field. In the spirit of a result by Yongqi Liang, we relate the arithmetic of rational points over finite extensions of $k$ to that of zero-cycles over $k$ for Kummer varieties over $k$. For example, for any Kummer…

Number Theory · Mathematics 2023-03-10 Francesca Balestrieri , Rachel Newton

We study the geometry of exceptional loci of birational contractions of hyper-K\"ahler fourfolds that are of K3$^{[2]}$-type. These loci are conic bundles over K3 surfaces and we determine their classes in the Brauer group. For this we use…

Algebraic Geometry · Mathematics 2022-12-12 Bert van Geemen , Grzegorz Kapustka

Let X be a smooth double cover of a geometrically ruled surface defined over a separably closed field of characteristic different from 2. The main result of this paper is a finite presentation of the 2-torsion in the Brauer group of X with…

Number Theory · Mathematics 2015-12-18 Brendan Creutz , Bianca Viray

We introduce an inseparable version of Kummer surfaces. It is defined as a supersingular K3 surface in characteristic 2 with 16 smooth rational curves forming a certain configuration and satisfying a suitable divisibility condition. The…

Algebraic Geometry · Mathematics 2024-03-06 Yuya Matsumoto

Let $X$ be a hyperkaehler manifold. Trianalytic subvarieties of $X$ are subvarieties which are complex analytic with respect to all complex structures induced by the hyperkaehler structure. Given a 2-dimensional complex torus $T$, the…

Algebraic Geometry · Mathematics 2007-05-23 D. Kaledin , M. Verbitsky

Let K be a global field, let S be a finite set of primes of K containing the archimedean primes and let A be an abelian variety over K. We generalize the duality theorem established in our paper "On Neron class groups of abelian varieties"…

Number Theory · Mathematics 2020-03-10 Cristian D. Gonzalez-Aviles

We study the Brauer group of an abelian variety A over an algebraically closed field of characteristic p focusing on the p-primary torsion, the key part of which is a certain quasi-algebraic unipotent group U_A. We determine its dimension…

Algebraic Geometry · Mathematics 2025-11-25 Livia Grammatica , Alexei N. Skorobogatov , Yuan Yang

We show that if over some number field there exists a certain diagonal plane cubic curve that is locally solvable everywhere, but that does not have points over any cubic galois extension of the number field, then the algebraic part of the…

Number Theory · Mathematics 2007-08-22 Ronald van Luijk

Let $X$ be a smooth projective geometrically connected variety defined over a number field $K$. We prove that the geometric \'etale cohomology of $X$ with $\mathbb{Q}/\mathbb{Z}$-coefficients has finitely many classes invariant under the…

Algebraic Geometry · Mathematics 2026-01-06 Davide Lombardo , Tamás Szamuely

Suppose $X$ is a torsor under an abelian variety $A$ over a number field. We show that any adelic point of $X$ that is orthogonal to the algebraic Brauer group of $X$ is orthogonal to the whole Brauer group of $X$. We also show that if…

Number Theory · Mathematics 2018-04-27 Brendan Creutz

We study K3 surfaces with complex multiplication following the classical work of Shimura on CM abelian varieties. After we translate the problem in terms of the arithmetic of the CM field and its id\`{e}les, we proceed to study some abelian…

Number Theory · Mathematics 2021-06-11 Domenico Valloni

This is an English translation of the author's 1989 note in Russian, published in a collection "Arithmetic and Geometry of Varieties" (V.E. Voskresenski, ed.), Kuibyshev State University, Kuibyshev, 1989, pp. 57--67. Let $X$ be be an…

Number Theory · Mathematics 2018-02-07 Yuri G. Zarhin

We compute the subgroup of the monodromy group of a generalized Kummer variety associated to equivalences of derived categories of abelian surfaces. The result was previously announced in arXiv:1201.0031. Mongardi showed that the subgroup…

Algebraic Geometry · Mathematics 2024-10-29 Eyal Markman