Properties

Label 86365.a.431825.1
Conductor $86365$
Discriminant $431825$
Mordell-Weil group \(\Z \oplus \Z \oplus \Z\)
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

$y^2 + (x^3 + x + 1)y = x^5 + 2x^4 + x^3 - 2x^2 + 2$ (homogenize, simplify)
$y^2 + (x^3 + xz^2 + z^3)y = x^5z + 2x^4z^2 + x^3z^3 - 2x^2z^4 + 2z^6$ (dehomogenize, simplify)
$y^2 = x^6 + 4x^5 + 10x^4 + 6x^3 - 7x^2 + 2x + 9$ (homogenize, minimize)

sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([2, 0, -2, 1, 2, 1]), R([1, 1, 0, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![2, 0, -2, 1, 2, 1], R![1, 1, 0, 1]);
 
sage: X = HyperellipticCurve(R([9, 2, -7, 6, 10, 4, 1]))
 
magma: X,pi:= SimplifiedModel(C);
 

Invariants

Conductor: \( N \)  \(=\)  \(86365\) \(=\) \( 5 \cdot 23 \cdot 751 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  \(=\)  \(431825\) \(=\) \( 5^{2} \cdot 23 \cdot 751 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  \(=\) \(252\) \(=\)  \( 2^{2} \cdot 3^{2} \cdot 7 \)
\( I_4 \)  \(=\) \(65097\) \(=\)  \( 3^{3} \cdot 2411 \)
\( I_6 \)  \(=\) \(7313067\) \(=\)  \( 3^{2} \cdot 73 \cdot 11131 \)
\( I_{10} \)  \(=\) \(-55273600\) \(=\)  \( - 2^{7} \cdot 5^{2} \cdot 23 \cdot 751 \)
\( J_2 \)  \(=\) \(63\) \(=\)  \( 3^{2} \cdot 7 \)
\( J_4 \)  \(=\) \(-2547\) \(=\)  \( - 3^{2} \cdot 283 \)
\( J_6 \)  \(=\) \(-53525\) \(=\)  \( - 5^{2} \cdot 2141 \)
\( J_8 \)  \(=\) \(-2464821\) \(=\)  \( - 3^{2} \cdot 47 \cdot 5827 \)
\( J_{10} \)  \(=\) \(-431825\) \(=\)  \( - 5^{2} \cdot 23 \cdot 751 \)
\( g_1 \)  \(=\) \(-992436543/431825\)
\( g_2 \)  \(=\) \(636869709/431825\)
\( g_3 \)  \(=\) \(8497629/17273\)

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
\((1 : 0 : 0)\) \((1 : -1 : 0)\) \((-1 : 0 : 1)\) \((0 : 1 : 1)\) \((-1 : 1 : 1)\) \((1 : 1 : 1)\)
\((0 : -2 : 1)\) \((-2 : 2 : 1)\) \((1 : -4 : 1)\) \((1 : 6 : 2)\) \((-2 : 7 : 1)\) \((1 : -19 : 2)\)
\((5 : 28 : 1)\) \((-4 : 34 : 3)\) \((-4 : 39 : 3)\) \((5 : -159 : 1)\) \((-7 : 177 : 6)\) \((-7 : 202 : 6)\)
Known points
\((1 : 0 : 0)\) \((1 : -1 : 0)\) \((-1 : 0 : 1)\) \((0 : 1 : 1)\) \((-1 : 1 : 1)\) \((1 : 1 : 1)\)
\((0 : -2 : 1)\) \((-2 : 2 : 1)\) \((1 : -4 : 1)\) \((1 : 6 : 2)\) \((-2 : 7 : 1)\) \((1 : -19 : 2)\)
\((5 : 28 : 1)\) \((-4 : 34 : 3)\) \((-4 : 39 : 3)\) \((5 : -159 : 1)\) \((-7 : 177 : 6)\) \((-7 : 202 : 6)\)
Known points
\((1 : -1 : 0)\) \((1 : 1 : 0)\) \((-1 : -1 : 1)\) \((-1 : 1 : 1)\) \((0 : -3 : 1)\) \((0 : 3 : 1)\)
\((1 : -5 : 1)\) \((1 : 5 : 1)\) \((-2 : -5 : 1)\) \((-2 : 5 : 1)\) \((-4 : -5 : 3)\) \((-4 : 5 : 3)\)
\((1 : -25 : 2)\) \((1 : 25 : 2)\) \((-7 : -25 : 6)\) \((-7 : 25 : 6)\) \((5 : -187 : 1)\) \((5 : 187 : 1)\)

magma: [C![-7,177,6],C![-7,202,6],C![-4,34,3],C![-4,39,3],C![-2,2,1],C![-2,7,1],C![-1,0,1],C![-1,1,1],C![0,-2,1],C![0,1,1],C![1,-19,2],C![1,-4,1],C![1,-1,0],C![1,0,0],C![1,1,1],C![1,6,2],C![5,-159,1],C![5,28,1]]; // minimal model
 
magma: [C![-7,-25,6],C![-7,25,6],C![-4,-5,3],C![-4,5,3],C![-2,-5,1],C![-2,5,1],C![-1,-1,1],C![-1,1,1],C![0,-3,1],C![0,3,1],C![1,-25,2],C![1,-5,1],C![1,-1,0],C![1,1,0],C![1,5,1],C![1,25,2],C![5,-187,1],C![5,187,1]]; // 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: \(\Z \oplus \Z \oplus \Z\)

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\((-1 : 0 : 1) + (0 : -2 : 1) - (1 : -1 : 0) - (1 : 0 : 0)\) \(x (x + z)\) \(=\) \(0,\) \(y\) \(=\) \(-2xz^2 - 2z^3\) \(0.597586\) \(\infty\)
\((-2 : 2 : 1) - (1 : -1 : 0)\) \(z (x + 2z)\) \(=\) \(0,\) \(y\) \(=\) \(2z^3\) \(0.208533\) \(\infty\)
\((-2 : 2 : 1) + (-1 : 1 : 1) - (1 : -1 : 0) - (1 : 0 : 0)\) \((x + z) (x + 2z)\) \(=\) \(0,\) \(y\) \(=\) \(-xz^2\) \(0.179162\) \(\infty\)
Generator $D_0$ Height Order
\((-1 : 0 : 1) + (0 : -2 : 1) - (1 : -1 : 0) - (1 : 0 : 0)\) \(x (x + z)\) \(=\) \(0,\) \(y\) \(=\) \(-2xz^2 - 2z^3\) \(0.597586\) \(\infty\)
\((-2 : 2 : 1) - (1 : -1 : 0)\) \(z (x + 2z)\) \(=\) \(0,\) \(y\) \(=\) \(2z^3\) \(0.208533\) \(\infty\)
\((-2 : 2 : 1) + (-1 : 1 : 1) - (1 : -1 : 0) - (1 : 0 : 0)\) \((x + z) (x + 2z)\) \(=\) \(0,\) \(y\) \(=\) \(-xz^2\) \(0.179162\) \(\infty\)
Generator $D_0$ Height Order
\((-1 : -1 : 1) + (0 : -3 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) \(x (x + z)\) \(=\) \(0,\) \(y\) \(=\) \(x^3 - 3xz^2 - 3z^3\) \(0.597586\) \(\infty\)
\((-2 : -5 : 1) - (1 : -1 : 0)\) \(z (x + 2z)\) \(=\) \(0,\) \(y\) \(=\) \(x^3 + xz^2 + 5z^3\) \(0.208533\) \(\infty\)
\((-2 : -5 : 1) + (-1 : 1 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) \((x + z) (x + 2z)\) \(=\) \(0,\) \(y\) \(=\) \(x^3 - xz^2 + z^3\) \(0.179162\) \(\infty\)

2-torsion field: 6.2.5153512325417.3

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(3\)   (upper bound)
Mordell-Weil rank: \(3\)
2-Selmer rank:\(3\)
Regulator: \( 0.022023 \)
Real period: \( 16.31186 \)
Tamagawa product: \( 2 \)
Torsion order:\( 1 \)
Leading coefficient: \( 0.718477 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor Cluster picture
\(5\) \(1\) \(2\) \(2\) \(( 1 + T )( 1 + 2 T + 5 T^{2} )\)
\(23\) \(1\) \(1\) \(1\) \(( 1 - T )( 1 + 9 T + 23 T^{2} )\)
\(751\) \(1\) \(1\) \(1\) \(( 1 + T )( 1 + 6 T + 751 T^{2} )\)

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?
\(2\) 2.20.2 no

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);