Properties

Label 7165.a.7165.1
Conductor 7165
Discriminant -7165
Mordell-Weil group \(\Z \times \Z \times \Z/{2}\Z\)
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

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

magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![0, 0, -2, 1, 1], R![1, 0, 0, 1]);
 
sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([0, 0, -2, 1, 1]), R([1, 0, 0, 1]));
 
magma: X,pi:= SimplifiedModel(C);
 
sage: X = HyperellipticCurve(R([1, 0, -8, 6, 4, 0, 1]))
 

Invariants

Conductor: \( N \)  =  \(7165\) = \( 5 \cdot 1433 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  =  \(-7165\) = \( - 5 \cdot 1433 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  = \(488\) =  \( 2^{3} \cdot 61 \)
\( I_4 \)  = \(12004\) =  \( 2^{2} \cdot 3001 \)
\( I_6 \)  = \(-2096536\) =  \( - 2^{3} \cdot 13 \cdot 19 \cdot 1061 \)
\( I_{10} \)  = \(-29347840\) =  \( - 2^{12} \cdot 5 \cdot 1433 \)
\( J_2 \)  = \(61\) =  \( 61 \)
\( J_4 \)  = \(30\) =  \( 2 \cdot 3 \cdot 5 \)
\( J_6 \)  = \(6284\) =  \( 2^{2} \cdot 1571 \)
\( J_8 \)  = \(95606\) =  \( 2 \cdot 7 \cdot 6829 \)
\( J_{10} \)  = \(-7165\) =  \( - 5 \cdot 1433 \)
\( g_1 \)  = \(-844596301/7165\)
\( g_2 \)  = \(-1361886/1433\)
\( g_3 \)  = \(-23382764/7165\)

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

Known points
\((1 : 0 : 0)\) \((1 : -1 : 0)\) \((0 : 0 : 1)\) \((0 : -1 : 1)\) \((1 : 0 : 1)\) \((-2 : 0 : 1)\)
\((1 : -2 : 1)\) \((1 : -4 : 2)\) \((1 : -5 : 2)\) \((-2 : 7 : 1)\) \((10 : 225 : 7)\) \((10 : -1568 : 7)\)

magma: [C![-2,0,1],C![-2,7,1],C![0,-1,1],C![0,0,1],C![1,-5,2],C![1,-4,2],C![1,-2,1],C![1,-1,0],C![1,0,0],C![1,0,1],C![10,-1568,7],C![10,225,7]];
 

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

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\((0 : 0 : 1) - (1 : -1 : 0)\) \(z x\) \(=\) \(0,\) \(y\) \(=\) \(0\) \(0.277008\) \(\infty\)
\((0 : -1 : 1) - (1 : -1 : 0)\) \(z x\) \(=\) \(0,\) \(y\) \(=\) \(-z^3\) \(0.228372\) \(\infty\)
\(D_0 - (1 : -1 : 0) - (1 : 0 : 0)\) \(x^2 + xz - z^2\) \(=\) \(0,\) \(y\) \(=\) \(-xz^2\) \(0\) \(2\)

2-torsion field: splitting field of \(x^{6} - x^{5} - 25 x^{4} - 84 x^{3} + 42 x^{2} - 8 x + 24\) with Galois group $S_4\times C_2$

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(2\)
Mordell-Weil rank: \(2\)
2-Selmer rank:\(3\)
Regulator: \( 0.058535 \)
Real period: \( 23.25245 \)
Tamagawa product: \( 1 \)
Torsion order:\( 2 \)
Leading coefficient: \( 0.340272 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor
\(5\) \(1\) \(1\) \(1\) \(( 1 - T )( 1 + 4 T + 5 T^{2} )\)
\(1433\) \(1\) \(1\) \(1\) \(( 1 - T )( 1 + 34 T + 1433 T^{2} )\)

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 \(\Q\).