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Related papers: The Brauer group and indecomposable (2,1)-cycles

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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

This paper investigates the homology of the Brauer algebras, interpreted as appropriate Tor-groups, and shows that it is closely related to the homology of the symmetric group. Our main results show that when the defining parameter of the…

Algebraic Topology · Mathematics 2023-06-13 Rachael Boyd , Richard Hepworth , Peter Patzt

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

The multiplicative group of a finite field is well known to be cyclic; in this note, we determine the finite fields whose multiplicative groups are direct sum indecomposable. We obtain our classification using a direct argument and also as…

Number Theory · Mathematics 2014-07-15 Sunil Chebolu , Keir Lockridge

We prove an extension of the Kato-Saito class field theory for smooth projective schemes over a finite field to schemes with singularities. As an application, we obtain Bloch's formula for the Chow groups of 0-cycles on such schemes. We…

Algebraic Geometry · Mathematics 2022-01-17 Mainak Ghosh , Amalendu Krishna

This note studies the Burnside problem for homeomorphism groups of compact connected manifolds. For surfaces, we prove that the identity component of the homeomorphism group is torsion-free precisely when the surface is not the sphere,…

Geometric Topology · Mathematics 2026-04-24 Donggyun Seo

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 provide an alternative proof that the Chow group of $1$-cycles on a Severi--Brauer variety associated to a biquaternion division algebra is torsion-free. There are three proofs of this result in the literature, all of which are due to…

Algebraic Geometry · Mathematics 2023-03-22 Eoin Mackall

Let X --> P^2 be a p-cyclic cover branched over a smooth, connected curve C of degree divisible by p, defined over a separably closed field of prime-to-p characteristic. We show that all (unramified) p-torsion Brauer classes on X that are…

Algebraic Geometry · Mathematics 2017-10-10 Colin Ingalls , Andrew Obus , Ekin Ozman , Bianca Viray

We give a new proof of the theorem stating that for any connected linear algebraic group G over an algebraically closed field k of characteristic 0 and for any closed connected subgroup H of G, the unramified Brauer group of G/H vanishes.

Algebraic Geometry · Mathematics 2021-01-05 Mikhail Borovoi

In this paper, motivated by a $\tau$-tilting version of the Brauer-Thrall Conjectures, we study general properties of band modules and their endomorphisms in the module category of a finite dimensional algebra. As an application we describe…

Representation Theory · Mathematics 2020-12-22 Sibylle Schroll , Hipolito Treffinger , Yadira Valdivieso

Let $k$ be a finitely generated field of characteristic $p>0$ and $X$ a smooth and proper scheme over $k$. Recent works of Cadoret, Hui and Tamagawa show that, if $X$ satisfies the $\ell$-adic Tate conjecture for divisors for every prime…

Number Theory · Mathematics 2021-05-18 Emiliano Ambrosi

We use twisted sheaves and their moduli spaces to study the Brauer group of a scheme. In particular, we (1) show how twisted methods can be efficiently used to re-prove the basic facts about the Brauer group and cohomological Brauer group…

Algebraic Geometry · Mathematics 2018-06-18 Max Lieblich

Controlled topology is one of the main tools for proving the isomorphism conjecture concerning the algebraic $K$-theory of group rings. In this article we dive into this machinery in two examples: when the group is infinite cyclic and when…

K-Theory and Homology · Mathematics 2019-08-05 Eugenia Ellis , Emanuel Rodríguez Cirone , Gisela Tartaglia , Santiago Vega

Let $\mathcal X$ be a regular variety, flat and proper over a complete regular curve over a finite field, such that the generic fiber $X$ is smooth and geometrically connected. We prove that the Brauer group of $\mathcal X$ is finite if and…

Number Theory · Mathematics 2018-08-07 Thomas H. Geisser

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 prove that the class of Brauer graph algebras coincides with the class of indecomposable idempotent algebras of biserial weighted surface algebras. These algebras are associated to triangulated surfaces with arbitrarily oriented…

Representation Theory · Mathematics 2018-08-23 Karin Erdmann , Andrzej Skowroński

We use recent advances in the local evaluation of Brauer elements to study the role played by {\it odd} torsion elements of the Brauer group in the arithmetic of diagonal quartic surfaces over {\it arbitrary} number fields. We show that…

Number Theory · Mathematics 2023-02-22 Evis Ieronymou

We study the torsion free generalized crystallographic groups with the indecomposable holonomy group which is isomorphic to either a cyclic group of order ${p^s}$ or a direct product of two cyclic groups of order ${p}$.

Group Theory · Mathematics 2007-05-23 V. A. Bovdi , P. M. Gudivok , V. P. Rudko

Let $X$ be a surface with geometric genus and irregularity zero which is defined over a number field $K$. Let $\mathscr{X}$ denote a smooth spread of $X$ over the spectrum of a Zariski open subset in the spectrum of the ring of integers and…

Number Theory · Mathematics 2022-03-01 Kalyan Banerjee , Kalyan Chakraborty