Properties

Label 464.a.29696.1
Conductor 464
Discriminant -29696
Mordell-Weil group \(\Z/{2}\Z \times \Z/{8}\Z\)
Sato-Tate group $\mathrm{USp}(4)$
\(\End(J_{\overline{\Q}}) \otimes \R\) \(\R\)
\(\End(J_{\overline{\Q}}) \otimes \Q\) \(\Q\)
\(\overline{\Q}\)-simple yes
\(\mathrm{GL}_2\)-type no

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Minimal equation

Minimal equation

Simplified equation

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

magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![0, 0, -2, -4, 3, 8], R![1, 1]);
 
sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([1, 2, -7, -16, 12, 32]))
 

$y^2 + (x + 1)y = 8x^5 + 3x^4 - 4x^3 - 2x^2$ (homogenize, simplify)
$y^2 + (xz^2 + z^3)y = 8x^5z + 3x^4z^2 - 4x^3z^3 - 2x^2z^4$ (dehomogenize, simplify)
$y^2 = 32x^5 + 12x^4 - 16x^3 - 7x^2 + 2x + 1$ (minimize, homogenize)

Invariants

\( N \)  =  \(464\) = \( 2^{4} \cdot 29 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
\( \Delta \)  =  \(-29696\) = \( - 2^{10} \cdot 29 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

magma: IgusaClebschInvariants(C); [Factorization(Integers()!a): a in $1];
 
sage: C.igusa_clebsch_invariants(); [factor(a) for a in _]
 

Igusa invariants

magma: IgusaInvariants(C); [Factorization(Integers()!a): a in $1];
 

G2 invariants

magma: G2Invariants(C);
 

\( I_2 \)  = \(5440\) =  \( 2^{6} \cdot 5 \cdot 17 \)
\( I_4 \)  = \(-336320\) =  \( - 2^{6} \cdot 5 \cdot 1051 \)
\( I_6 \)  = \(-642023936\) =  \( - 2^{9} \cdot 1253953 \)
\( I_{10} \)  = \(-121634816\) =  \( - 2^{22} \cdot 29 \)
\( J_2 \)  = \(680\) =  \( 2^{3} \cdot 5 \cdot 17 \)
\( J_4 \)  = \(22770\) =  \( 2 \cdot 3^{2} \cdot 5 \cdot 11 \cdot 23 \)
\( J_6 \)  = \(1180736\) =  \( 2^{6} \cdot 19 \cdot 971 \)
\( J_8 \)  = \(71106895\) =  \( 5 \cdot 223 \cdot 63773 \)
\( J_{10} \)  = \(-29696\) =  \( - 2^{10} \cdot 29 \)
\( g_1 \)  = \(-141985700000/29\)
\( g_2 \)  = \(-6991813125/29\)
\( g_3 \)  = \(-533176100/29\)

Automorphism group

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

Rational points

magma: [C![-1,-2,2],C![0,-1,1],C![0,0,1],C![1,-6,2],C![1,0,0]];
 

Points: \((0 : 0 : 1),\, (1 : 0 : 0),\, (0 : -1 : 1),\, (-1 : -2 : 2),\, (1 : -6 : 2)\)

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

Number of rational Weierstrass points: \(3\)

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);
 

This curve is locally solvable everywhere.

Mordell-Weil group of the Jacobian:

magma: MordellWeilGroupGenus2(Jacobian(C));
 

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

Generator Height Order
\(2x - z\) \(=\) \(0,\) \(4y\) \(=\) \(-3z^3\) \(0\) \(2\)
\(x\) \(=\) \(0,\) \(y\) \(=\) \(0\) \(0\) \(8\)

2-torsion field: 3.1.116.1

BSD invariants

Analytic rank: \(0\)
Mordell-Weil rank: \(0\)
2-Selmer rank:\(2\)
Regulator: \( 1 \)
Real period: \( 14.42143 \)
Tamagawa product: \( 4 \)
Torsion order:\( 16 \)
Leading coefficient: \( 0.225334 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor
\(2\) \(10\) \(4\) \(4\) \(1 + T + 2 T^{2}\)
\(29\) \(1\) \(1\) \(1\) \(( 1 + T )( 1 + 2 T + 29 T^{2} )\)

Sato-Tate group

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

Decomposition of the Jacobian

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

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 \(\Q\).