Properties

Label 1200.a.30000.1
Conductor $1200$
Discriminant $-30000$
Mordell-Weil group \(\Z/{2}\Z \times \Z/{8}\Z\)
Sato-Tate group $\mathrm{SU}(2)\times\mathrm{SU}(2)$
\(\End(J_{\overline{\Q}}) \otimes \R\) \(\R \times \R\)
\(\End(J_{\overline{\Q}}) \otimes \Q\) \(\Q \times \Q\)
\(\End(J) \otimes \Q\) \(\Q \times \Q\)
\(\overline{\Q}\)-simple no
\(\mathrm{GL}_2\)-type yes

Related objects

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Show commands for: SageMath / Magma

Minimal equation

Minimal equation

Simplified equation

$y^2 + (x^3 + x)y = -2x^4 + x^2 + 3$ (homogenize, simplify)
$y^2 + (x^3 + xz^2)y = -2x^4z^2 + x^2z^4 + 3z^6$ (dehomogenize, simplify)
$y^2 = x^6 - 6x^4 + 5x^2 + 12$ (minimize, homogenize)

sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([3, 0, 1, 0, -2]), R([0, 1, 0, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![3, 0, 1, 0, -2], R![0, 1, 0, 1]);
 
sage: X = HyperellipticCurve(R([12, 0, 5, 0, -6, 0, 1]))
 
magma: X,pi:= SimplifiedModel(C);
 

Invariants

Conductor: \( N \)  \(=\)  \(1200\) \(=\) \( 2^{4} \cdot 3 \cdot 5^{2} \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  \(=\)  \(-30000\) \(=\) \( - 2^{4} \cdot 3 \cdot 5^{4} \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  \(=\) \(600\) \(=\)  \( 2^{3} \cdot 3 \cdot 5^{2} \)
\( I_4 \)  \(=\) \(18744\) \(=\)  \( 2^{3} \cdot 3 \cdot 11 \cdot 71 \)
\( I_6 \)  \(=\) \(4690524\) \(=\)  \( 2^{2} \cdot 3 \cdot 390877 \)
\( I_{10} \)  \(=\) \(120000\) \(=\)  \( 2^{6} \cdot 3 \cdot 5^{4} \)
\( J_2 \)  \(=\) \(300\) \(=\)  \( 2^{2} \cdot 3 \cdot 5^{2} \)
\( J_4 \)  \(=\) \(626\) \(=\)  \( 2 \cdot 313 \)
\( J_6 \)  \(=\) \(-198336\) \(=\)  \( - 2^{6} \cdot 3 \cdot 1033 \)
\( J_8 \)  \(=\) \(-14973169\) \(=\)  \( - 131 \cdot 114299 \)
\( J_{10} \)  \(=\) \(30000\) \(=\)  \( 2^{4} \cdot 3 \cdot 5^{4} \)
\( g_1 \)  \(=\) \(81000000\)
\( g_2 \)  \(=\) \(563400\)
\( g_3 \)  \(=\) \(-595008\)

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: \((1 : 0 : 0),\, (1 : -1 : 0),\, (-2 : 5 : 1),\, (2 : -5 : 1)\)
All points: \((1 : 0 : 0),\, (1 : -1 : 0),\, (-2 : 5 : 1),\, (2 : -5 : 1)\)
All points: \((1 : -1 : 0),\, (1 : 1 : 0),\, (-2 : 0 : 1),\, (2 : 0 : 1)\)

magma: [C![-2,5,1],C![1,-1,0],C![1,0,0],C![2,-5,1]]; // minimal model
 
magma: [C![-2,0,1],C![1,-1,0],C![1,1,0],C![2,0,1]]; // simplified model
 

Number of rational Weierstrass points: \(2\)

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: \(\Z/{2}\Z \times \Z/{8}\Z\)

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\(D_0 - (1 : -1 : 0) - (1 : 0 : 0)\) \(x^2 + z^2\) \(=\) \(0,\) \(y\) \(=\) \(0\) \(0\) \(2\)
\((2 : -5 : 1) - (1 : 0 : 0)\) \(z (x - 2z)\) \(=\) \(0,\) \(y\) \(=\) \(-x^3 + 3z^3\) \(0\) \(8\)
Generator $D_0$ Height Order
\(D_0 - (1 : -1 : 0) - (1 : 0 : 0)\) \(x^2 + z^2\) \(=\) \(0,\) \(y\) \(=\) \(0\) \(0\) \(2\)
\((2 : -5 : 1) - (1 : 0 : 0)\) \(z (x - 2z)\) \(=\) \(0,\) \(y\) \(=\) \(-x^3 + 3z^3\) \(0\) \(8\)
Generator $D_0$ Height Order
\(D_0 - (1 : -1 : 0) - (1 : 1 : 0)\) \(x^2 + z^2\) \(=\) \(0,\) \(y\) \(=\) \(x^3 + xz^2\) \(0\) \(2\)
\((2 : 0 : 1) - (1 : 1 : 0)\) \(z (x - 2z)\) \(=\) \(0,\) \(y\) \(=\) \(-x^3 + xz^2 + 6z^3\) \(0\) \(8\)

2-torsion field: \(\Q(\zeta_{12})\)

BSD invariants

Hasse-Weil conjecture: verified
Analytic rank: \(0\)
Mordell-Weil rank: \(0\)
2-Selmer rank:\(2\)
Regulator: \( 1 \)
Real period: \( 22.62148 \)
Tamagawa product: \( 4 \)
Torsion order:\( 16 \)
Leading coefficient: \( 0.353460 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor Cluster picture
\(2\) \(4\) \(4\) \(1\) \(1 + T + 2 T^{2}\)
\(3\) \(1\) \(1\) \(1\) \(( 1 + T )( 1 + 3 T^{2} )\)
\(5\) \(2\) \(4\) \(4\) \(( 1 - T )^{2}\)

Sato-Tate group

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

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 80.a
  Elliptic curve isogeny class 15.a

Endomorphisms of the Jacobian

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

Endomorphism ring over \(\Q\):

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

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