Properties

Label 832.a.832.1
Conductor 832
Discriminant -832
Mordell-Weil group \(\Z/{8}\Z\)
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

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

magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![-1, 2, 1, -1, 0, 1], R![0, 1, 0, 1]);
 
sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([-1, 2, 1, -1, 0, 1]), R([0, 1, 0, 1]));
 
magma: X,pi:= SimplifiedModel(C);
 
sage: X = HyperellipticCurve(R([-4, 8, 5, -4, 2, 4, 1]))
 

Invariants

Conductor: \( N \)  =  \(832\) = \( 2^{6} \cdot 13 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  =  \(-832\) = \( - 2^{6} \cdot 13 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  = \(2176\) =  \( 2^{7} \cdot 17 \)
\( I_4 \)  = \(-8384\) =  \( - 2^{6} \cdot 131 \)
\( I_6 \)  = \(-6349824\) =  \( - 2^{10} \cdot 3^{2} \cdot 13 \cdot 53 \)
\( I_{10} \)  = \(-3407872\) =  \( - 2^{18} \cdot 13 \)
\( J_2 \)  = \(272\) =  \( 2^{4} \cdot 17 \)
\( J_4 \)  = \(3170\) =  \( 2 \cdot 5 \cdot 317 \)
\( J_6 \)  = \(51008\) =  \( 2^{6} \cdot 797 \)
\( J_8 \)  = \(956319\) =  \( 3 \cdot 7 \cdot 13 \cdot 31 \cdot 113 \)
\( J_{10} \)  = \(-832\) =  \( - 2^{6} \cdot 13 \)
\( g_1 \)  = \(-23262937088/13\)
\( g_2 \)  = \(-996749440/13\)
\( g_3 \)  = \(-58965248/13\)

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

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

Number of rational Weierstrass points: \(1\)

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: \(\Z/{8}\Z\)

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\(D_0 - (1 : -1 : 0) - (1 : 0 : 0)\) \(x^2 + xz - z^2\) \(=\) \(0,\) \(y\) \(=\) \(-xz^2 + z^3\) \(0\) \(8\)

2-torsion field: 6.2.346112.1

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(0\)
Mordell-Weil rank: \(0\)
2-Selmer rank:\(1\)
Regulator: \( 1 \)
Real period: \( 21.14821 \)
Tamagawa product: \( 1 \)
Torsion order:\( 8 \)
Leading coefficient: \( 0.330440 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor
\(2\) \(6\) \(6\) \(1\) \(1 + T + 2 T^{2}\)
\(13\) \(1\) \(1\) \(1\) \(( 1 + T )( 1 + 2 T + 13 T^{2} )\)

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 \(\Q\).