Properties

Label 1311.a.814131.1
Conductor 1311
Discriminant -814131
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

Related objects

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Minimal equation

Minimal equation

Simplified equation

$y^2 + xy = x^5 + 5x^4 + 5x^3 + 4x^2 + x$ (homogenize, simplify)
$y^2 + xz^2y = x^5z + 5x^4z^2 + 5x^3z^3 + 4x^2z^4 + xz^5$ (dehomogenize, simplify)
$y^2 = 4x^5 + 20x^4 + 20x^3 + 17x^2 + 4x$ (minimize, homogenize)

magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![0, 1, 4, 5, 5, 1], R![0, 1]);
 
sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([0, 1, 4, 5, 5, 1]), R([0, 1]));
 
magma: X,pi:= SimplifiedModel(C);
 
sage: X = HyperellipticCurve(R([0, 4, 17, 20, 20, 4]))
 

Invariants

Conductor: \( N \)  =  \(1311\) = \( 3 \cdot 19 \cdot 23 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  =  \(-814131\) = \( - 3^{4} \cdot 19 \cdot 23^{2} \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  = \(-2400\) =  \( - 2^{5} \cdot 3 \cdot 5^{2} \)
\( I_4 \)  = \(32640\) =  \( 2^{7} \cdot 3 \cdot 5 \cdot 17 \)
\( I_6 \)  = \(-55062336\) =  \( - 2^{6} \cdot 3 \cdot 7 \cdot 53 \cdot 773 \)
\( I_{10} \)  = \(-3334680576\) =  \( - 2^{12} \cdot 3^{4} \cdot 19 \cdot 23^{2} \)
\( J_2 \)  = \(-300\) =  \( - 2^{2} \cdot 3 \cdot 5^{2} \)
\( J_4 \)  = \(3410\) =  \( 2 \cdot 5 \cdot 11 \cdot 31 \)
\( J_6 \)  = \(4761\) =  \( 3^{2} \cdot 23^{2} \)
\( J_8 \)  = \(-3264100\) =  \( - 2^{2} \cdot 5^{2} \cdot 7 \cdot 4663 \)
\( J_{10} \)  = \(-814131\) =  \( - 3^{4} \cdot 19 \cdot 23^{2} \)
\( g_1 \)  = \(30000000000/10051\)
\( g_2 \)  = \(3410000000/30153\)
\( g_3 \)  = \(-10000/19\)

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

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

All points: \((1 : 0 : 0),\, (0 : 0 : 1),\, (-1 : -1 : 1),\, (-1 : 2 : 1),\, (-4 : 2 : 1)\)

magma: [C![-4,2,1],C![-1,-1,1],C![-1,2,1],C![0,0,1],C![1,0,0]];
 

Number of rational Weierstrass points: \(3\)

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
\((-4 : 2 : 1) - (1 : 0 : 0)\) \(x + 4z\) \(=\) \(0,\) \(y\) \(=\) \(2z^3\) \(0\) \(2\)
\((-4 : 2 : 1) + (-1 : 2 : 1) - 2 \cdot(1 : 0 : 0)\) \((x + z) (x + 4z)\) \(=\) \(0,\) \(y\) \(=\) \(2z^3\) \(0\) \(8\)

2-torsion field: 3.1.76.1

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(0\)
Mordell-Weil rank: \(0\)
2-Selmer rank:\(2\)
Regulator: \( 1 \)
Real period: \( 13.75349 \)
Tamagawa product: \( 8 \)
Torsion order:\( 16 \)
Leading coefficient: \( 0.429796 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor
\(3\) \(4\) \(1\) \(4\) \(( 1 - T )( 1 + 3 T^{2} )\)
\(19\) \(1\) \(1\) \(1\) \(( 1 - T )( 1 - 4 T + 19 T^{2} )\)
\(23\) \(2\) \(1\) \(2\) \(( 1 + T )( 1 - 8 T + 23 T^{2} )\)

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 \(\Q\).