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Related papers: Brauer classes not split by genus one curves

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We prove that every Brauer class over a field splits over a torsor under an abelian variety. If the index of the class is not congruent to 2 modulo 4, we show that the Albanese variety of any smooth curve of positive genus that splits the…

Algebraic Geometry · Mathematics 2018-11-14 Wei Ho , Max Lieblich

Let K be a field. Let A be a central simple algebra over K and let X be the associated Brauer-Severi variety over K. It has recently been asked if there exists a genus 1 curve C over K such that K(C) splits A. In other words, is there a…

Algebraic Geometry · Mathematics 2012-07-23 Aise Johan de Jong , Wei Ho

We prove new results on splitting Brauer classes by genus 1 curves, settling in particular the case of degree 7 classes over global fields. Though our method is cohomological in nature, and proceeds by considering the more difficult problem…

Number Theory · Mathematics 2021-06-09 Benjamin Antieau , Asher Auel

We examine when division algebras can share common splitting fields of certain types. In particular, we show that one can find fields for which one has infinitely many Brauer classes of the same index and period at least 3, all…

Rings and Algebras · Mathematics 2023-08-28 Daniel Krashen , Max Lieblich

In this paper we develop techniques for computing the relative Brauer group of curves, focusing particularly on the case where the genus is 1. We use these techniques to show that the relative Brauer group may be infinite (for certain…

Number Theory · Mathematics 2011-06-10 Mirela Ciperiani , Daniel Krashen

Suppose $C$ is a smooth projective curve of genus 1 over a perfect field $F$, and $E$ is its Jacobian. In the case that $C$ has no $F$-rational points, so that $C$ and $E$ are not isomorphic, $C$ is an $E$-torsor with a class $\delta(C)\in…

Algebraic Geometry · Mathematics 2025-07-10 Niranjan Ramachandran , Jonathan Rosenberg

We consider the question: which elliptic curves appear as the Jacobian of a smooth curve of genus one splitting a Severi--Brauer variety? We provide three new examples. First, we show that if $E$ is any elliptic curve over an algebraically…

Algebraic Geometry · Mathematics 2024-01-22 Eoin Mackall , Nick Rekuski

We develop a framework for describing vector bundles on $\mu_n$-gerbes over curves and illustrate the construction through two detailed examples. Using the interpretation of Brauer classes as obstructions to descending determinantal line…

Algebraic Geometry · Mathematics 2026-01-27 Ting Gong

Unlike the classical Brauer group of a field, the Brauer-Grothendieck group of a singular scheme need not be torsion. We show that there exist integral normal projective surfaces over a large field of positive characteristic with…

Algebraic Geometry · Mathematics 2022-05-23 Louis Esser

We fit the Brauer group of a $\mu_r$-gerbe over a (possibly arbitrarily singular) stacky curve into an exact sequence and give characterizations for when it is short exact and conditions for when it splits. We also give a precise formula…

Algebraic Geometry · Mathematics 2025-07-25 Martin Bishop

Let $F$ be a field complete with respect to a discrete valuation whose residue field is perfect of characteristic $p>0$. We prove that every smooth, projective, geometrically irreducible curve of genus one defined over $F$ with a non-zero…

Number Theory · Mathematics 2012-02-14 Ambrus Pal

Let $X$ be a smooth proper curve defined over a field $k$. The representability of the relative Picard functor is obstructed by a class $\alpha\in\mathrm{Br}(\mathrm{Pic}_{X/k})$. We show the associated division algebra on…

Algebraic Geometry · Mathematics 2019-08-09 Qixiao Ma

In this paper we study division algebras over the function fields of curves over $\Q_p$. The first and main tool is to view these fields as function fields over nonsingular $S$ which are projective of relative dimension 1 over the $p$ adic…

Algebraic Geometry · Mathematics 2007-05-23 David J. Saltman

We prove that if q is a power of an odd prime then there is no genus-2 curve over F_q whose Jacobian has characteristic polynomial of Frobenius equal to x^4 + (2-2q)x^2 + q^2. Our proof uses the Brauer relations in a biquadratic extension…

Number Theory · Mathematics 2007-05-23 Everett W. Howe

This paper began as an investigation of the question of whether $D_1 \otimes_F D_2$ is a domain where the $D_i$ are division algebras and $F$ is an algebraically closed field contained in their centers. We present an example where the…

Algebraic Geometry · Mathematics 2011-06-29 Louis Rowen , David J Saltman

Working over imperfect fields, we give a comprehensive classification of genus-one curves that are regular but not geometrically regular, extending the known case of geometrically reduced curves. The description is given intrinsically, in…

Algebraic Geometry · Mathematics 2022-11-09 Stefan Schröer

We show that there exist genus one curves of every index over the rational numbers, answering affirmatively a question of Lang and Tate. The proof is "elementary" in the sense that it does not assume the finiteness of any Shafarevich-Tate…

Number Theory · Mathematics 2007-05-23 Pete L. Clark

Let $X$ be a smooth projective variety with a fibration into varieties that either satisfy a condition on representability of zero-cycles or that are torsors under an abelian variety. We study the classes in the Brauer group that never…

Number Theory · Mathematics 2019-06-25 Masahiro Nakahara

We study abelian surfaces defined over finite fields which do not contain any possibly singular curve of genus less than or equal to $3$. Firstly, we complete and expand the characterisation of isogeny classes of abelian surfaces with no…

Algebraic Geometry · Mathematics 2026-03-12 Elena Berardini , Alejandro Giangreco Maidana , Stefano Marseglia

The genus gen(D) of a finite-dimensional central division algebra D over a field F is defined as the collection of classes [D'] in the Brauer group Br(F), where D' is a central division F-algebra having the same maximal subfields as D. For…

Rings and Algebras · Mathematics 2014-07-21 Sergey V. Tikhonov
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