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Related papers: Curves of genus 2 with sqrt2 multiplication

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In this survey we study the genus 2 curves with $(n, n)$-split Jacobian for even $n$.

Algebraic Geometry · Mathematics 2013-05-20 N. Pjero , M. Ramasaço , T. Shaska

We address the question of existence of absolutely simple abelian varieties of dimension 2 with everywhere good reduction over quadratic fields. The emphasis will be given to the construction of pairs $(K,C)$, where $K$ is a quadratic…

Number Theory · Mathematics 2023-10-11 Andrzej Dabrowski , Mohammad Sadek

We extend the formulae of classical invariant theory for the Jacobian of a genus one curve of degree $n \le 4$ to curves of arbitrary degree. To do this, we associate to each genus one normal curve of degree $n$, an $n \times n$ alternating…

Number Theory · Mathematics 2019-01-02 Tom Fisher

We describe a method to determine all the isomorphism classes of principal polarizations of the modular abelian surfaces $A_f$ with quaternionic multiplication attached to a normalized newform $f$ without complex multiplication. We include…

Number Theory · Mathematics 2015-05-13 Josep Gonzalez , Jordi Guardia

We give a method for finding rational equations of genus 2 curves whose jacobians are abelian varieties $A_f$ attached by Shimura to normalized newforms $f \in S_2( \Gamma_0(N))$. We present all the curves corresponding to principally…

Number Theory · Mathematics 2026-02-13 Enrique González-Jiménez , Josep González , Jordi Guàrdia

We generalize the group law of curves of degree three by chords and tangents to the Jacobi variety of a hyperelliptic curve. In the case of genus 2 we accomplish the construction by a cubic parabola. We derive explicit rational formulas for…

Algebraic Geometry · Mathematics 2007-05-23 Frank Leitenberger

We outline a general algorithm for computing an explicit model over a number field of any curve of genus 2 whose (unpolarized) Jacobian is isomorphic to the product of two elliptic curves with CM by the same order in an imaginary quadratic…

Number Theory · Mathematics 2018-03-30 Fernando Rodriguez Villegas

Several curves of genus 2 are known, such that the equations of motion of the Kowalewski top are linearized on their Jacobians. One can expect from transcendental approaches via solutions of equations of motion in theta-functions, that…

Algebraic Geometry · Mathematics 2016-09-07 Franck Leprevost , Dimitri Markushevich

The refined Humbert invariant is a positive definite quadratic form intrinsically attached to a curve $C$ of genus 2. This invariant is an algebraic generalization of the (usual) Humbert invariant. This invariant is useful because many…

Number Theory · Mathematics 2026-04-27 Harun Kir

We determine what isogeny classes of supersingular abelian surfaces over a finite field k of characteristic 2 contain jacobians. We deal with this problem in a direct way by computing explicitly the zeta function of all supersingular curves…

Number Theory · Mathematics 2007-05-23 Daniel Maisner , Enric Nart

We prove that there is only a finite number of genus 2 curves C defined over Q such that there exists a nonconstant morphism pi:X_1(N) --->C defined over Q and the jacobian of C, J(C), is a Q-factor of the new part of the jacobian of…

Number Theory · Mathematics 2010-06-21 Enrique Gonzalez-Jimenez , Josep Gonzalez

A set of multi-homogeneous equations for the Jacobian of a genus two curve is given. The approach used is to write down affine equations for the Jacobian minus various tranlations of the Theta-divisor by [2]-division points, and then to…

Algebraic Geometry · Mathematics 2015-07-28 Mark Heiligman

We provide a complete enumeration of all quotients of genus $0, 1$ and $2$ of the Shimura curves $X_0^D(N)$ over $\mathbb{Q}$ by non-trivial subgroups of Atkin--Lehner involutions. For all $1270$ genus $1$ quotients $X$ with $N$ squarefree,…

Number Theory · Mathematics 2025-10-29 Oana Padurariu , Frederick Saia

We study the set of isomorphism classes of principal polarizations on abelian varieties of GL2-type. As applications of our results, we construct examples of curves C, C'/\Q of genus two which are nonisomorphic over \bar \Q and share…

Number Theory · Mathematics 2015-06-26 Josep Gonzalez , Jordi Guardia , Victor Rotger

We establish the existence of hyperelliptic curves of genus $g\ge 2$ defined over $\mathbb{Q}$ whose Jacobians possess rational torsion points of order $N$ where $N=4g^2+2g-2$ or $4g^2+ 2g -4$. For $N=2g^2+7g+1$, we introduce a…

Number Theory · Mathematics 2024-10-21 Hamide Kuru , Mohammad Sadek

We determine the isogeny classes of abelian surfaces over F_q whose group of F_q-rational points has order divisible by q^2. We also solve the same problem for Jacobians of genus-2 curves.

Algebraic Geometry · Mathematics 2013-10-08 Michael E. Zieve

We prove that for any number field $K$ and any fixed genus $g \geq 2$, there are infinitely many non-isomorphic hyperelliptic curves of genus $g$ over $K$ whose Jacobians have rank over $K$ equal to each of 0, 1, or 2. As an example of our…

Number Theory · Mathematics 2026-04-22 Stevan Gajović , Sun Woo Park

We determine all genus 2 curves, defined over $\mathbb C$, which have simultaneously degree 2 and 3 elliptic subcovers. The locus of such curves has three irreducible 1-dimensional genus zero components in $\mathcal M_2$. For each component…

Algebraic Geometry · Mathematics 2012-09-04 Tony Shaska

We give a general framework for uniform, constant-time one-and two-dimensional scalar multiplication algorithms for elliptic curves and Jacobians of genus 2 curves that operate by projecting to the x-line or Kummer surface, where we can…

Number Theory · Mathematics 2015-10-23 Ping Ngai Chung , Craig Costello , Benjamin Smith

In 2000, Galbraith and McKee heuristically derived a formula that estimates the probability that a randomly chosen elliptic curve over a fixed finite prime field has a prime number of rational points. We show how their heuristics can be…

Number Theory · Mathematics 2013-02-05 Wouter Castryck , Amanda Folsom , Hendrik Hubrechts , Andrew V. Sutherland