Properties

Label 86516.a.346064.1
Conductor $86516$
Discriminant $-346064$
Mordell-Weil group \(\Z \oplus \Z \oplus \Z\)
Sato-Tate group $\mathrm{USp}(4)$
\(\End(J_{\overline{\Q}}) \otimes \R\) \(\R\)
\(\End(J_{\overline{\Q}}) \otimes \Q\) \(\Q\)
\(\End(J) \otimes \Q\) \(\Q\)
\(\overline{\Q}\)-simple yes
\(\mathrm{GL}_2\)-type no

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Minimal equation

Minimal equation

Simplified equation

$y^2 + y = x^6 - 4x^5 + 2x^4 + 2x^3 - x$ (homogenize, simplify)
$y^2 + z^3y = x^6 - 4x^5z + 2x^4z^2 + 2x^3z^3 - xz^5$ (dehomogenize, simplify)
$y^2 = 4x^6 - 16x^5 + 8x^4 + 8x^3 - 4x + 1$ (homogenize, minimize)

sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([0, -1, 0, 2, 2, -4, 1]), R([1]));
 
magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![0, -1, 0, 2, 2, -4, 1], R![1]);
 
sage: X = HyperellipticCurve(R([1, -4, 0, 8, 8, -16, 4]))
 
magma: X,pi:= SimplifiedModel(C);
 

Invariants

Conductor: \( N \)  \(=\)  \(86516\) \(=\) \( 2^{2} \cdot 43 \cdot 503 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  \(=\)  \(-346064\) \(=\) \( - 2^{4} \cdot 43 \cdot 503 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  \(=\) \(248\) \(=\)  \( 2^{3} \cdot 31 \)
\( I_4 \)  \(=\) \(2773\) \(=\)  \( 47 \cdot 59 \)
\( I_6 \)  \(=\) \(170663\) \(=\)  \( 17 \cdot 10039 \)
\( I_{10} \)  \(=\) \(-43258\) \(=\)  \( - 2 \cdot 43 \cdot 503 \)
\( J_2 \)  \(=\) \(248\) \(=\)  \( 2^{3} \cdot 31 \)
\( J_4 \)  \(=\) \(714\) \(=\)  \( 2 \cdot 3 \cdot 7 \cdot 17 \)
\( J_6 \)  \(=\) \(10960\) \(=\)  \( 2^{4} \cdot 5 \cdot 137 \)
\( J_8 \)  \(=\) \(552071\) \(=\)  \( 13 \cdot 42467 \)
\( J_{10} \)  \(=\) \(-346064\) \(=\)  \( - 2^{4} \cdot 43 \cdot 503 \)
\( g_1 \)  \(=\) \(-58632501248/21629\)
\( g_2 \)  \(=\) \(-680664768/21629\)
\( g_3 \)  \(=\) \(-42130240/21629\)

sage: C.igusa_clebsch_invariants(); [factor(a) for a in _]
 
magma: IgusaClebschInvariants(C); IgusaInvariants(C); G2Invariants(C);
 

Automorphism group

\(\mathrm{Aut}(X)\)\(\simeq\) $C_2$
magma: AutomorphismGroup(C); IdentifyGroup($1);
 
\(\mathrm{Aut}(X_{\overline{\Q}})\)\(\simeq\) $C_2$
magma: AutomorphismGroup(ChangeRing(C,AlgebraicClosure(Rationals()))); IdentifyGroup($1);
 

Rational points

Known points
\((1 : -1 : 0)\) \((1 : 1 : 0)\) \((0 : 0 : 1)\) \((0 : -1 : 1)\) \((1 : 0 : 1)\) \((1 : -1 : 1)\)
\((-1 : 2 : 1)\) \((-1 : -3 : 1)\) \((-1 : 3 : 2)\) \((1 : -3 : 2)\) \((3 : -3 : 4)\) \((1 : -5 : 2)\)
\((-1 : -11 : 2)\) \((1 : -13 : 3)\) \((-2 : 14 : 1)\) \((1 : -14 : 3)\) \((-2 : -15 : 1)\) \((3 : -61 : 4)\)
\((5 : -3469 : 24)\) \((5 : -10355 : 24)\)
Known points
\((1 : -1 : 0)\) \((1 : 1 : 0)\) \((0 : 0 : 1)\) \((0 : -1 : 1)\) \((1 : 0 : 1)\) \((1 : -1 : 1)\)
\((-1 : 2 : 1)\) \((-1 : -3 : 1)\) \((-1 : 3 : 2)\) \((1 : -3 : 2)\) \((3 : -3 : 4)\) \((1 : -5 : 2)\)
\((-1 : -11 : 2)\) \((1 : -13 : 3)\) \((-2 : 14 : 1)\) \((1 : -14 : 3)\) \((-2 : -15 : 1)\) \((3 : -61 : 4)\)
\((5 : -3469 : 24)\) \((5 : -10355 : 24)\)
Known points
\((1 : -2 : 0)\) \((1 : 2 : 0)\) \((0 : -1 : 1)\) \((0 : 1 : 1)\) \((1 : -1 : 1)\) \((1 : 1 : 1)\)
\((1 : -2 : 2)\) \((1 : 2 : 2)\) \((1 : -1 : 3)\) \((1 : 1 : 3)\) \((-1 : -5 : 1)\) \((-1 : 5 : 1)\)
\((-1 : -14 : 2)\) \((-1 : 14 : 2)\) \((-2 : -29 : 1)\) \((-2 : 29 : 1)\) \((3 : -58 : 4)\) \((3 : 58 : 4)\)
\((5 : -6886 : 24)\) \((5 : 6886 : 24)\)

magma: [C![-2,-15,1],C![-2,14,1],C![-1,-11,2],C![-1,-3,1],C![-1,2,1],C![-1,3,2],C![0,-1,1],C![0,0,1],C![1,-14,3],C![1,-13,3],C![1,-5,2],C![1,-3,2],C![1,-1,0],C![1,-1,1],C![1,0,1],C![1,1,0],C![3,-61,4],C![3,-3,4],C![5,-10355,24],C![5,-3469,24]]; // minimal model
 
magma: [C![-2,-29,1],C![-2,29,1],C![-1,-14,2],C![-1,-5,1],C![-1,5,1],C![-1,14,2],C![0,-1,1],C![0,1,1],C![1,-1,3],C![1,1,3],C![1,-2,2],C![1,2,2],C![1,-2,0],C![1,-1,1],C![1,1,1],C![1,2,0],C![3,-58,4],C![3,58,4],C![5,-6886,24],C![5,6886,24]]; // simplified model
 

Number of rational Weierstrass points: \(0\)

magma: #Roots(HyperellipticPolynomials(SimplifiedModel(C)));
 

This curve is locally solvable everywhere.

magma: f,h:=HyperellipticPolynomials(C); g:=4*f+h^2; HasPointsEverywhereLocally(g,2) and (#Roots(ChangeRing(g,RealField())) gt 0 or LeadingCoefficient(g) gt 0);
 

Mordell-Weil group of the Jacobian

Group structure: \(\Z \oplus \Z \oplus \Z\)

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\(2 \cdot(0 : -1 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) \(x^2\) \(=\) \(0,\) \(y\) \(=\) \(xz^2 - z^3\) \(0.358125\) \(\infty\)
\((0 : -1 : 1) + (1 : -3 : 2) - (1 : -1 : 0) - (1 : 1 : 0)\) \(x (2x - z)\) \(=\) \(0,\) \(4y\) \(=\) \(5xz^2 - 4z^3\) \(0.276448\) \(\infty\)
\((0 : -1 : 1) - (1 : 1 : 0)\) \(z x\) \(=\) \(0,\) \(y\) \(=\) \(-x^3 - z^3\) \(0.166828\) \(\infty\)
Generator $D_0$ Height Order
\(2 \cdot(0 : -1 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) \(x^2\) \(=\) \(0,\) \(y\) \(=\) \(xz^2 - z^3\) \(0.358125\) \(\infty\)
\((0 : -1 : 1) + (1 : -3 : 2) - (1 : -1 : 0) - (1 : 1 : 0)\) \(x (2x - z)\) \(=\) \(0,\) \(4y\) \(=\) \(5xz^2 - 4z^3\) \(0.276448\) \(\infty\)
\((0 : -1 : 1) - (1 : 1 : 0)\) \(z x\) \(=\) \(0,\) \(y\) \(=\) \(-x^3 - z^3\) \(0.166828\) \(\infty\)
Generator $D_0$ Height Order
\(2 \cdot(0 : -1 : 1) - (1 : -2 : 0) - (1 : 2 : 0)\) \(x^2\) \(=\) \(0,\) \(y\) \(=\) \(2xz^2 - z^3\) \(0.358125\) \(\infty\)
\(D_0 - (1 : -2 : 0) - (1 : 2 : 0)\) \(x (2x - z)\) \(=\) \(0,\) \(4y\) \(=\) \(10xz^2 - 7z^3\) \(0.276448\) \(\infty\)
\((0 : -1 : 1) - (1 : 2 : 0)\) \(z x\) \(=\) \(0,\) \(y\) \(=\) \(-2x^3 - z^3\) \(0.166828\) \(\infty\)

2-torsion field: 6.4.5537024.1

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(3\)   (upper bound)
Mordell-Weil rank: \(3\)
2-Selmer rank:\(3\)
Regulator: \( 0.015669 \)
Real period: \( 17.79644 \)
Tamagawa product: \( 3 \)
Torsion order:\( 1 \)
Leading coefficient: \( 0.836557 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor Cluster picture
\(2\) \(2\) \(4\) \(3\) \(1 + 2 T + 2 T^{2}\)
\(43\) \(1\) \(1\) \(1\) \(( 1 - T )( 1 - T + 43 T^{2} )\)
\(503\) \(1\) \(1\) \(1\) \(( 1 - T )( 1 + 30 T + 503 T^{2} )\)

Galois representations

The mod-$\ell$ Galois representation has maximal image \(\GSp(4,\F_\ell)\) for all primes \( \ell \) .

Sato-Tate group

\(\mathrm{ST}\)\(\simeq\) $\mathrm{USp}(4)$
\(\mathrm{ST}^0\)\(\simeq\) \(\mathrm{USp}(4)\)

Decomposition of the Jacobian

Simple over \(\overline{\Q}\)

magma: HeuristicDecompositionFactors(C);
 

Endomorphisms of the Jacobian

Not of \(\GL_2\)-type over \(\Q\)

Endomorphism ring over \(\Q\):

\(\End (J_{})\)\(\simeq\)\(\Z\)
\(\End (J_{}) \otimes \Q \)\(\simeq\)\(\Q\)
\(\End (J_{}) \otimes \R\)\(\simeq\) \(\R\)

All \(\overline{\Q}\)-endomorphisms of the Jacobian are defined over \(\Q\).

magma: //Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
 

magma: HeuristicIsGL2(C); HeuristicEndomorphismDescription(C); HeuristicEndomorphismFieldOfDefinition(C);
 

magma: HeuristicIsGL2(C : Geometric := true); HeuristicEndomorphismDescription(C : Geometric := true); HeuristicEndomorphismLatticeDescription(C);