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Related papers: Chai's conjecture for semiabelian Jacobians

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The paper studies representation theoretic aspects of a nonabelian version of the Jacobian for a smooth complex projective surface $X$ introduced in [R1]. The sheaf of reductive Lie algebras $\bf\calG$ associated to the nonabelian Jacobian…

Algebraic Geometry · Mathematics 2016-11-25 Igor Reider

We define an algebraic analogue, in the case of jacobians of curves, of the height jump divisor introduced recently by R. Hain. We give explicit combinatorial formulae for the height jump for families of semistable curves using labelled…

Algebraic Geometry · Mathematics 2016-03-15 Owen Biesel , David Holmes , Robin de Jong

We partially generalize the theory of semihomogeneous bundles on an abelian variety $A$ developed by Mukai. This involves considering abelian subvarieties $Y\subset X_A=A\times\hat{A}$ and studying coherent sheaves on $A$ invariant under…

Algebraic Geometry · Mathematics 2011-12-08 Alexander Polishchuk

The Coleman-Oort conjecture says that for large $g$ there are no positive-dimensional Shimura subvarieties of $\mathsf{A}_g$ generically contained in the Jacobian locus. Counterexamples are known for $g\leq 7$. They can all be constructed…

Algebraic Geometry · Mathematics 2022-07-05 Diego Conti , Alessandro Ghigi , Roberto Pignatelli

Jacobian conjectures (that nonsingular implies a global inverse) for rational everywhere defined maps of real n-space to itself are considered, with no requirement for a constant Jacobian determinant or a rational inverse. The birational…

Algebraic Geometry · Mathematics 2013-11-18 L. Andrew Campbell

This is the first paper of a series of three. Here we give an abstract definition of the relative compactified Jacobian of a family of reduced curves. We prove that, under some mild assumptions on the family of curves, the fibres of the…

Algebraic Geometry · Mathematics 2025-05-14 Marco Fava , Nicola Pagani , Filippo Viviani

We prove the integral Hodge conjecture for one-cycles on a principally polarized complex abelian variety whose minimal class is algebraic. In particular, any product of Jacobians of smooth projective curves over the complex numbers…

Algebraic Geometry · Mathematics 2023-02-09 Thorsten Beckmann , Olivier de Gaay Fortman

We show that any polarized abelian variety over a finite field is covered by a Jacobian whose dimension is bounded by an explicit constant. We do this by first proving an effective version of Poonen's Bertini theorem over finite fields,…

Algebraic Geometry · Mathematics 2019-07-09 Juliette Bruce , Wanlin Li

In a preceding paper we introduced a notion of compatibility between a Jacobi structure and a Riemannian structure on a smooth manifold. We proved that in the case of fundamental examples of Jacobi structures : Poisson structures, contact…

Differential Geometry · Mathematics 2019-11-13 Yacine Aït Amrane , Ahmed Zeglaoui

We construct three families of pairs of genus 2 curves over a field K, whose Jacobians are isomorphic as unpolarized abelian varieties. Each family is parameterized by an open subset of the Projective line over K. Our construction is based…

Algebraic Geometry · Mathematics 2024-10-07 Raghda Abdellatif

We prove the geometric Bombieri-Lang conjecture for projective varieties which have finite maps to abelian varieties over function fields of characteristic 0. This generalizes the recent results of Xie-Yuan, which require either the…

Number Theory · Mathematics 2026-03-03 Guoquan Gao

In this article we study maps with nilpotent Jacobian in $\mathbb{R}^n$ distinguishing the cases when the rows of $JH$ are linearly dependent over $\mathbb{R}$ and when they are linearly independent over $\mathbb{R}.$ In the linearly…

Dynamical Systems · Mathematics 2018-11-12 Álvaro Castañeda , Maximiliano Machado-Higuera

Let $\frak{p}$ be a prime ideal of $\mathbb{F}_q[T]$. Let $J_0(\frak{p})$ be the Jacobian variety of the Drinfeld modular curve $X_0(\frak{p})$. Let $\Phi$ be the component group of $J_0(\frak{p})$ at the place $1/T$. We use graph…

Number Theory · Mathematics 2016-12-26 Mihran Papikian

Let $\phi:\,X\rightarrow Y$ be a (possibly ramified) cover between two algebraic curves of positive genus. We develop tools that may identify the Prym variety of $\phi$, up to isogeny, as the Jacobian of a quotient curve $C$ in the Galois…

Algebraic Geometry · Mathematics 2020-03-18 Davide Lombardo , Elisa Lorenzo García , Christophe Ritzenthaler , Jeroen Sijsling

In this paper we introduce the notion of infinite dimensional Jacobi structure to describe the geometrical structure of a class of nonlocal Hamiltonian systems which appear naturally when applying reciprocal transformations to Hamiltonian…

Differential Geometry · Mathematics 2009-10-13 Si-Qi Liu , Youjin Zhang

We construct some natural cycles with trivial regulator in the higher Chow groups of Jacobians. For hyperelliptic curves we use a criterion due to J. Lewis to prove that the cycles we construct are indecomposable, and then use a…

Algebraic Geometry · Mathematics 2007-05-23 Alberto Collino , Najmuddin Fakhruddin

We give a structure theorem for the $m$-torsion of the Jacobian of a general superelliptic curve $y^m=F(x)$. We study existence of torsion on curves of the form $y^q=x^p-x+a$ over finite fields of characteristic $p$. We apply those results…

Algebraic Geometry · Mathematics 2021-06-10 Wojciech Wawrów

The Beilinson--Bloch conjecture is a generalization of the Birch and Swinnerton-Dyer conjecture, which relates the ranks of Chow groups of smooth projective varieties over global fields to the order of vanishing of $L$-functions. We prove…

Number Theory · Mathematics 2026-02-24 Matt Broe

Poonen and Stoll have shown that the reduced Shafarevich-Tate group of a principally polarized abelian variety over a global field can have order twice a square (the odd case) as well as a square (the even case). For a curve over a global…

Number Theory · Mathematics 2007-05-23 Bruce W. Jordan , Ron Livné

We introduce a general abstract notion of fine compactified Jacobian for nodal curves of arbitrary genus. We focus on genus 1 and prove combinatorial classification results for fine compactified Jacobians in the case of a single nodal curve…

Algebraic Geometry · Mathematics 2022-03-01 Nicola Pagani , Orsola Tommasi