Properties

Label 3776.c.241664.1
Conductor $3776$
Discriminant $241664$
Mordell-Weil group \(\Z/{7}\Z\)
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

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

sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([-1, 2, -2, 1, -1, 1]), R([1, 0, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![-1, 2, -2, 1, -1, 1], R![1, 0, 1]);
 
sage: X = HyperellipticCurve(R([-3, 8, -6, 4, -3, 4]))
 
magma: X,pi:= SimplifiedModel(C);
 

Invariants

Conductor: \( N \)  \(=\)  \(3776\) \(=\) \( 2^{6} \cdot 59 \)
magma: Conductor(LSeries(C: ExcFactors:=[*<2,Valuation(3776,2),R![1, -1]>*])); Factorization($1);
 
Discriminant: \( \Delta \)  \(=\)  \(241664\) \(=\) \( 2^{12} \cdot 59 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  \(=\) \(68\) \(=\)  \( 2^{2} \cdot 17 \)
\( I_4 \)  \(=\) \(-23\) \(=\)  \( -23 \)
\( I_6 \)  \(=\) \(844\) \(=\)  \( 2^{2} \cdot 211 \)
\( I_{10} \)  \(=\) \(944\) \(=\)  \( 2^{4} \cdot 59 \)
\( J_2 \)  \(=\) \(136\) \(=\)  \( 2^{3} \cdot 17 \)
\( J_4 \)  \(=\) \(832\) \(=\)  \( 2^{6} \cdot 13 \)
\( J_6 \)  \(=\) \(-2496\) \(=\)  \( - 2^{6} \cdot 3 \cdot 13 \)
\( J_8 \)  \(=\) \(-257920\) \(=\)  \( - 2^{7} \cdot 5 \cdot 13 \cdot 31 \)
\( J_{10} \)  \(=\) \(241664\) \(=\)  \( 2^{12} \cdot 59 \)
\( g_1 \)  \(=\) \(11358856/59\)
\( g_2 \)  \(=\) \(510952/59\)
\( g_3 \)  \(=\) \(-11271/59\)

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

All points: \((1 : 0 : 0),\, (1 : 0 : 1),\, (1 : -2 : 1)\)
All points: \((1 : 0 : 0),\, (1 : 0 : 1),\, (1 : -2 : 1)\)
All points: \((1 : 0 : 0),\, (1 : -2 : 1),\, (1 : 2 : 1)\)

magma: [C![1,-2,1],C![1,0,0],C![1,0,1]]; // minimal model
 
magma: [C![1,-2,1],C![1,0,0],C![1,2,1]]; // simplified model
 

Number of rational Weierstrass points: \(1\)

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: \(\Z/{7}\Z\)

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\((1 : 0 : 1) - (1 : 0 : 0)\) \(x - z\) \(=\) \(0,\) \(y\) \(=\) \(0\) \(0\) \(7\)
Generator $D_0$ Height Order
\((1 : 0 : 1) - (1 : 0 : 0)\) \(x - z\) \(=\) \(0,\) \(y\) \(=\) \(0\) \(0\) \(7\)
Generator $D_0$ Height Order
\((1 : 2 : 1) - (1 : 0 : 0)\) \(x - z\) \(=\) \(0,\) \(y\) \(=\) \(x^2z + z^3\) \(0\) \(7\)

2-torsion field: 5.1.60416.1

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(0\)
Mordell-Weil rank: \(0\)
2-Selmer rank:\(0\)
Regulator: \( 1 \)
Real period: \( 6.943384 \)
Tamagawa product: \( 7 \)
Torsion order:\( 7 \)
Leading coefficient: \( 0.991912 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor Cluster picture
\(2\) \(6\) \(12\) \(7\) \(1 - T\)
\(59\) \(1\) \(1\) \(1\) \(( 1 - T )( 1 - 4 T + 59 T^{2} )\)

Galois representations

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

Prime \(\ell\) mod-\(\ell\) image Is torsion prime?
\(2\) 2.6.1 no
\(7\) not computed yes

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);