Properties

Label 7643.a.7643.1
Conductor 7643
Discriminant -7643
Mordell-Weil group \(\Z \times \Z\)
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

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

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

Invariants

Conductor: \( N \)  \(=\)  \(7643\) \(=\) \( 7643 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  \(=\)  \(-7643\) \(=\) \( -7643 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  \(=\) \(-88\) \(=\)  \( - 2^{3} \cdot 11 \)
\( I_4 \)  \(=\) \(26404\) \(=\)  \( 2^{2} \cdot 7 \cdot 23 \cdot 41 \)
\( I_6 \)  \(=\) \(-746200\) \(=\)  \( - 2^{3} \cdot 5^{2} \cdot 7 \cdot 13 \cdot 41 \)
\( I_{10} \)  \(=\) \(-31305728\) \(=\)  \( - 2^{12} \cdot 7643 \)
\( J_2 \)  \(=\) \(-11\) \(=\)  \( -11 \)
\( J_4 \)  \(=\) \(-270\) \(=\)  \( - 2 \cdot 3^{3} \cdot 5 \)
\( J_6 \)  \(=\) \(452\) \(=\)  \( 2^{2} \cdot 113 \)
\( J_8 \)  \(=\) \(-19468\) \(=\)  \( - 2^{2} \cdot 31 \cdot 157 \)
\( J_{10} \)  \(=\) \(-7643\) \(=\)  \( -7643 \)
\( g_1 \)  \(=\) \(161051/7643\)
\( g_2 \)  \(=\) \(-359370/7643\)
\( g_3 \)  \(=\) \(-54692/7643\)

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
\((1 : 0 : 0)\) \((1 : -1 : 0)\) \((0 : 0 : 1)\) \((0 : -1 : 1)\) \((-1 : -1 : 1)\) \((-1 : 1 : 1)\)
\((-2 : 2 : 1)\) \((-2 : 5 : 1)\) \((1 : 5 : 2)\) \((1 : -14 : 2)\)

magma: [C![-2,2,1],C![-2,5,1],C![-1,-1,1],C![-1,1,1],C![0,-1,1],C![0,0,1],C![1,-14,2],C![1,-1,0],C![1,0,0],C![1,5,2]];
 

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: \(\Z \times \Z\)

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\((0 : 0 : 1) - (1 : -1 : 0)\) \(z x\) \(=\) \(0,\) \(y\) \(=\) \(0\) \(0.111469\) \(\infty\)
\(D_0 - 2 \cdot(1 : -1 : 0)\) \(z^2\) \(=\) \(0,\) \(y\) \(=\) \(x^2z\) \(0.143198\) \(\infty\)

2-torsion field: 6.0.489152.1

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(2\)
Mordell-Weil rank: \(2\)
2-Selmer rank:\(2\)
Regulator: \( 0.015846 \)
Real period: \( 23.29220 \)
Tamagawa product: \( 1 \)
Torsion order:\( 1 \)
Leading coefficient: \( 0.369099 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor Cluster picture
\(7643\) \(1\) \(1\) \(1\) \(( 1 + T )( 1 - 156 T + 7643 T^{2} )\)

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 \(\Q\).