Properties

Label 99656.b.797248.1
Conductor $99656$
Discriminant $-797248$
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

$y^2 + (x + 1)y = x^6 + 3x^4 - 2x^3 - 2x^2$ (homogenize, simplify)
$y^2 + (xz^2 + z^3)y = x^6 + 3x^4z^2 - 2x^3z^3 - 2x^2z^4$ (dehomogenize, simplify)
$y^2 = 4x^6 + 12x^4 - 8x^3 - 7x^2 + 2x + 1$ (homogenize, minimize)

sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([0, 0, -2, -2, 3, 0, 1]), R([1, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![0, 0, -2, -2, 3, 0, 1], R![1, 1]);
 
sage: X = HyperellipticCurve(R([1, 2, -7, -8, 12, 0, 4]))
 
magma: X,pi:= SimplifiedModel(C);
 

Invariants

Conductor: \( N \)  \(=\)  \(99656\) \(=\) \( 2^{3} \cdot 12457 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  \(=\)  \(-797248\) \(=\) \( - 2^{6} \cdot 12457 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  \(=\) \(192\) \(=\)  \( 2^{6} \cdot 3 \)
\( I_4 \)  \(=\) \(20508\) \(=\)  \( 2^{2} \cdot 3 \cdot 1709 \)
\( I_6 \)  \(=\) \(37500\) \(=\)  \( 2^{2} \cdot 3 \cdot 5^{5} \)
\( I_{10} \)  \(=\) \(-3188992\) \(=\)  \( - 2^{8} \cdot 12457 \)
\( J_2 \)  \(=\) \(96\) \(=\)  \( 2^{5} \cdot 3 \)
\( J_4 \)  \(=\) \(-3034\) \(=\)  \( - 2 \cdot 37 \cdot 41 \)
\( J_6 \)  \(=\) \(89028\) \(=\)  \( 2^{2} \cdot 3^{2} \cdot 2473 \)
\( J_8 \)  \(=\) \(-164617\) \(=\)  \( -164617 \)
\( J_{10} \)  \(=\) \(-797248\) \(=\)  \( - 2^{6} \cdot 12457 \)
\( g_1 \)  \(=\) \(-127401984/12457\)
\( g_2 \)  \(=\) \(41942016/12457\)
\( g_3 \)  \(=\) \(-12820032/12457\)

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
\((1 : -1 : 0)\) \((1 : 1 : 0)\) \((0 : 0 : 1)\) \((0 : -1 : 1)\) \((1 : 0 : 1)\) \((-1 : -2 : 1)\)
\((-1 : -1 : 2)\) \((-1 : 2 : 1)\) \((1 : -2 : 1)\) \((-1 : -3 : 2)\) \((1 : -5 : 2)\) \((1 : -7 : 2)\)
\((2 : 8 : 1)\) \((-1 : -8 : 3)\) \((-1 : -10 : 3)\) \((2 : -11 : 1)\) \((-3 : -41 : 2)\) \((-3 : 45 : 2)\)
\((3 : -155 : 8)\) \((3 : -549 : 8)\)
Known points
\((1 : -1 : 0)\) \((1 : 1 : 0)\) \((0 : 0 : 1)\) \((0 : -1 : 1)\) \((1 : 0 : 1)\) \((-1 : -2 : 1)\)
\((-1 : -1 : 2)\) \((-1 : 2 : 1)\) \((1 : -2 : 1)\) \((-1 : -3 : 2)\) \((1 : -5 : 2)\) \((1 : -7 : 2)\)
\((2 : 8 : 1)\) \((-1 : -8 : 3)\) \((-1 : -10 : 3)\) \((2 : -11 : 1)\) \((-3 : -41 : 2)\) \((-3 : 45 : 2)\)
\((3 : -155 : 8)\) \((3 : -549 : 8)\)
Known points
\((1 : -2 : 0)\) \((1 : 2 : 0)\) \((0 : -1 : 1)\) \((0 : 1 : 1)\) \((1 : -2 : 1)\) \((1 : 2 : 1)\)
\((-1 : -2 : 2)\) \((-1 : 2 : 2)\) \((1 : -2 : 2)\) \((1 : 2 : 2)\) \((-1 : -2 : 3)\) \((-1 : 2 : 3)\)
\((-1 : -4 : 1)\) \((-1 : 4 : 1)\) \((2 : -19 : 1)\) \((2 : 19 : 1)\) \((-3 : -86 : 2)\) \((-3 : 86 : 2)\)
\((3 : -394 : 8)\) \((3 : 394 : 8)\)

magma: [C![-3,-41,2],C![-3,45,2],C![-1,-10,3],C![-1,-8,3],C![-1,-3,2],C![-1,-2,1],C![-1,-1,2],C![-1,2,1],C![0,-1,1],C![0,0,1],C![1,-7,2],C![1,-5,2],C![1,-2,1],C![1,-1,0],C![1,0,1],C![1,1,0],C![2,-11,1],C![2,8,1],C![3,-549,8],C![3,-155,8]]; // minimal model
 
magma: [C![-3,-86,2],C![-3,86,2],C![-1,-2,3],C![-1,2,3],C![-1,-2,2],C![-1,-4,1],C![-1,2,2],C![-1,4,1],C![0,-1,1],C![0,1,1],C![1,-2,2],C![1,2,2],C![1,-2,1],C![1,-2,0],C![1,2,1],C![1,2,0],C![2,-19,1],C![2,19,1],C![3,-394,8],C![3,394,8]]; // 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
\(2 \cdot(0 : -1 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) \(x^2\) \(=\) \(0,\) \(y\) \(=\) \(-xz^2 - z^3\) \(0.280394\) \(\infty\)
\((0 : -1 : 1) - (1 : -1 : 0)\) \(z x\) \(=\) \(0,\) \(y\) \(=\) \(x^3 - z^3\) \(0.295042\) \(\infty\)
\((-1 : -1 : 2) + (1 : -2 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) \((x - z) (2x + z)\) \(=\) \(0,\) \(4y\) \(=\) \(-5xz^2 - 3z^3\) \(0.197872\) \(\infty\)
Generator $D_0$ Height Order
\(2 \cdot(0 : -1 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) \(x^2\) \(=\) \(0,\) \(y\) \(=\) \(-xz^2 - z^3\) \(0.280394\) \(\infty\)
\((0 : -1 : 1) - (1 : -1 : 0)\) \(z x\) \(=\) \(0,\) \(y\) \(=\) \(x^3 - z^3\) \(0.295042\) \(\infty\)
\((-1 : -1 : 2) + (1 : -2 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) \((x - z) (2x + z)\) \(=\) \(0,\) \(4y\) \(=\) \(-5xz^2 - 3z^3\) \(0.197872\) \(\infty\)
Generator $D_0$ Height Order
\(2 \cdot(0 : -1 : 1) - (1 : -2 : 0) - (1 : 2 : 0)\) \(x^2\) \(=\) \(0,\) \(y\) \(=\) \(-xz^2 - z^3\) \(0.280394\) \(\infty\)
\((0 : -1 : 1) - (1 : -2 : 0)\) \(z x\) \(=\) \(0,\) \(y\) \(=\) \(2x^3 + xz^2 - z^3\) \(0.295042\) \(\infty\)
\(D_0 - (1 : -2 : 0) - (1 : 2 : 0)\) \((x - z) (2x + z)\) \(=\) \(0,\) \(4y\) \(=\) \(-9xz^2 - 5z^3\) \(0.197872\) \(\infty\)

2-torsion field: 6.4.3188992.1

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(3\)   (upper bound)
Mordell-Weil rank: \(3\)
2-Selmer rank:\(3\)
Regulator: \( 0.011407 \)
Real period: \( 16.42962 \)
Tamagawa product: \( 6 \)
Torsion order:\( 1 \)
Leading coefficient: \( 1.124513 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor Cluster picture
\(2\) \(3\) \(6\) \(6\) \(1 + T\)
\(12457\) \(1\) \(1\) \(1\) \(( 1 + T )( 1 - 140 T + 12457 T^{2} )\)

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);