Properties

Label 6912.f.884736.2
Conductor $6912$
Discriminant $-884736$
Mordell-Weil group \(\Z \oplus \Z/{4}\Z\)
Sato-Tate group $N(\mathrm{U}(1)\times\mathrm{SU}(2))$
\(\End(J_{\overline{\Q}}) \otimes \R\) \(\C \times \R\)
\(\End(J_{\overline{\Q}}) \otimes \Q\) \(\mathsf{CM} \times \Q\)
\(\End(J) \otimes \Q\) \(\Q \times \Q\)
\(\overline{\Q}\)-simple no
\(\mathrm{GL}_2\)-type yes

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Minimal equation

Minimal equation

Simplified equation

$y^2 = x^6 + 5x^4 + 9x^2 + 6$ (homogenize, simplify)
$y^2 = x^6 + 5x^4z^2 + 9x^2z^4 + 6z^6$ (dehomogenize, simplify)
$y^2 = x^6 + 5x^4 + 9x^2 + 6$ (homogenize, minimize)

sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([6, 0, 9, 0, 5, 0, 1]), R([]));
 
magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![6, 0, 9, 0, 5, 0, 1], R![]);
 
sage: X = HyperellipticCurve(R([6, 0, 9, 0, 5, 0, 1]))
 
magma: X,pi:= SimplifiedModel(C);
 

Invariants

Conductor: \( N \)  \(=\)  \(6912\) \(=\) \( 2^{8} \cdot 3^{3} \)
magma: Conductor(LSeries(C: ExcFactors:=[*<2,Valuation(6912,2),R![1]>*])); Factorization($1);
 
Discriminant: \( \Delta \)  \(=\)  \(-884736\) \(=\) \( - 2^{15} \cdot 3^{3} \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  \(=\) \(1080\) \(=\)  \( 2^{3} \cdot 3^{3} \cdot 5 \)
\( I_4 \)  \(=\) \(333\) \(=\)  \( 3^{2} \cdot 37 \)
\( I_6 \)  \(=\) \(119313\) \(=\)  \( 3^{5} \cdot 491 \)
\( I_{10} \)  \(=\) \(108\) \(=\)  \( 2^{2} \cdot 3^{3} \)
\( J_2 \)  \(=\) \(4320\) \(=\)  \( 2^{5} \cdot 3^{3} \cdot 5 \)
\( J_4 \)  \(=\) \(774048\) \(=\)  \( 2^{5} \cdot 3 \cdot 11 \cdot 733 \)
\( J_6 \)  \(=\) \(184098816\) \(=\)  \( 2^{13} \cdot 3^{2} \cdot 11 \cdot 227 \)
\( J_8 \)  \(=\) \(49039144704\) \(=\)  \( 2^{8} \cdot 3^{2} \cdot 11 \cdot 19 \cdot 101839 \)
\( J_{10} \)  \(=\) \(884736\) \(=\)  \( 2^{15} \cdot 3^{3} \)
\( g_1 \)  \(=\) \(1700611200000\)
\( g_2 \)  \(=\) \(70535124000\)
\( g_3 \)  \(=\) \(3883334400\)

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

Automorphism group

\(\mathrm{Aut}(X)\)\(\simeq\) $C_2^2$
magma: AutomorphismGroup(C); IdentifyGroup($1);
 
\(\mathrm{Aut}(X_{\overline{\Q}})\)\(\simeq\) $C_2^2$
magma: AutomorphismGroup(ChangeRing(C,AlgebraicClosure(Rationals()))); IdentifyGroup($1);
 

Rational points

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

magma: [C![1,-1,0],C![1,1,0]]; // minimal model
 
magma: [C![1,-1/2,0],C![1,1/2,0]]; // 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: \(\Z \oplus \Z/{4}\Z\)

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\(D_0 - 2 \cdot(1 : -1 : 0)\) \(z^2\) \(=\) \(0,\) \(y\) \(=\) \(x^3\) \(1.002364\) \(\infty\)
\(D_0 - (1 : -1 : 0) - (1 : 1 : 0)\) \(x^2 + z^2\) \(=\) \(0,\) \(y\) \(=\) \(z^3\) \(0\) \(4\)
Generator $D_0$ Height Order
\(D_0 - 2 \cdot(1 : -1 : 0)\) \(z^2\) \(=\) \(0,\) \(y\) \(=\) \(x^3\) \(1.002364\) \(\infty\)
\(D_0 - (1 : -1 : 0) - (1 : 1 : 0)\) \(x^2 + z^2\) \(=\) \(0,\) \(y\) \(=\) \(z^3\) \(0\) \(4\)
Generator $D_0$ Height Order
\(D_0 - 2 \cdot(1 : -1/2 : 0)\) \(z^2\) \(=\) \(0,\) \(y\) \(=\) \(1/2x^3\) \(1.002364\) \(\infty\)
\(D_0 - (1 : -1/2 : 0) - (1 : 1/2 : 0)\) \(x^2 + z^2\) \(=\) \(0,\) \(y\) \(=\) \(1/2z^3\) \(0\) \(4\)

2-torsion field: 8.0.47775744.4

BSD invariants

Hasse-Weil conjecture: verified
Analytic rank: \(1\)
Mordell-Weil rank: \(1\)
2-Selmer rank:\(2\)
Regulator: \( 1.002364 \)
Real period: \( 6.076164 \)
Tamagawa product: \( 2 \)
Torsion order:\( 4 \)
Leading coefficient: \( 0.761316 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor Cluster picture
\(2\) \(8\) \(15\) \(2\) \(1\)
\(3\) \(3\) \(3\) \(1\) \(1 + T\)

Galois representations

For primes $\ell \ge 5$ the Galois representation data has not been computed for this curve since it is not generic.

For primes $\ell \le 3$, the image of the mod-$\ell$ Galois representation is listed in the table below, whenever it is not all of $\GSp(4,\F_\ell)$.

Prime \(\ell\) mod-\(\ell\) image Is torsion prime?
\(2\) 2.45.1 yes
\(3\) 3.270.2 no

Sato-Tate group

\(\mathrm{ST}\)\(\simeq\) $N(\mathrm{U}(1)\times\mathrm{SU}(2))$
\(\mathrm{ST}^0\)\(\simeq\) \(\mathrm{U}(1)\times\mathrm{SU}(2)\)

Decomposition of the Jacobian

Splits over \(\Q\)

Decomposes up to isogeny as the product of the non-isogenous elliptic curve isogeny classes:
  Elliptic curve isogeny class 288.a
  Elliptic curve isogeny class 24.a

magma: HeuristicDecompositionFactors(C);
 

Endomorphisms of the Jacobian

Of \(\GL_2\)-type over \(\Q\)

Endomorphism ring over \(\Q\):

\(\End (J_{})\)\(\simeq\)an order of index \(2\) in \(\Z \times \Z\)
\(\End (J_{}) \otimes \Q \)\(\simeq\)\(\Q\) \(\times\) \(\Q\)
\(\End (J_{}) \otimes \R\)\(\simeq\) \(\R \times \R\)

Smallest field over which all endomorphisms are defined:
Galois number field \(K = \Q (a) \simeq \) \(\Q(\sqrt{-1}) \) with defining polynomial \(x^{2} + 1\)

Not of \(\GL_2\)-type over \(\overline{\Q}\)

Endomorphism ring over \(\overline{\Q}\):

\(\End (J_{\overline{\Q}})\)\(\simeq\)an order of index \(4\) in \(\Z \times \Z [\sqrt{-1}]\)
\(\End (J_{\overline{\Q}}) \otimes \Q \)\(\simeq\)\(\Q\) \(\times\) \(\Q(\sqrt{-1}) \)
\(\End (J_{\overline{\Q}}) \otimes \R\)\(\simeq\) \(\R \times \C\)

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);