Properties

Label 12949.a.12949.1
Conductor $12949$
Discriminant $12949$
Mordell-Weil group \(\Z \oplus \Z\)
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

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

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

Invariants

Conductor: \( N \)  \(=\)  \(12949\) \(=\) \( 23 \cdot 563 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  \(=\)  \(12949\) \(=\) \( 23 \cdot 563 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  \(=\) \(280\) \(=\)  \( 2^{3} \cdot 5 \cdot 7 \)
\( I_4 \)  \(=\) \(2368\) \(=\)  \( 2^{6} \cdot 37 \)
\( I_6 \)  \(=\) \(196632\) \(=\)  \( 2^{3} \cdot 3^{2} \cdot 2731 \)
\( I_{10} \)  \(=\) \(51796\) \(=\)  \( 2^{2} \cdot 23 \cdot 563 \)
\( J_2 \)  \(=\) \(140\) \(=\)  \( 2^{2} \cdot 5 \cdot 7 \)
\( J_4 \)  \(=\) \(422\) \(=\)  \( 2 \cdot 211 \)
\( J_6 \)  \(=\) \(-148\) \(=\)  \( - 2^{2} \cdot 37 \)
\( J_8 \)  \(=\) \(-49701\) \(=\)  \( - 3 \cdot 16567 \)
\( J_{10} \)  \(=\) \(12949\) \(=\)  \( 23 \cdot 563 \)
\( g_1 \)  \(=\) \(53782400000/12949\)
\( g_2 \)  \(=\) \(1157968000/12949\)
\( g_3 \)  \(=\) \(-2900800/12949\)

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
\((1 : 0 : 0)\) \((0 : 0 : 1)\) \((-1 : 0 : 1)\) \((0 : -1 : 1)\) \((1 : 0 : 1)\) \((-1 : -1 : 1)\)
\((1 : -1 : 1)\) \((-2 : 0 : 1)\) \((-2 : -1 : 1)\) \((1 : -10 : 4)\) \((1 : -54 : 4)\)
Known points
\((1 : 0 : 0)\) \((0 : 0 : 1)\) \((-1 : 0 : 1)\) \((0 : -1 : 1)\) \((1 : 0 : 1)\) \((-1 : -1 : 1)\)
\((1 : -1 : 1)\) \((-2 : 0 : 1)\) \((-2 : -1 : 1)\) \((1 : -10 : 4)\) \((1 : -54 : 4)\)
Known points
\((1 : 0 : 0)\) \((0 : -1 : 1)\) \((0 : 1 : 1)\) \((-1 : -1 : 1)\) \((-1 : 1 : 1)\) \((1 : -1 : 1)\)
\((1 : 1 : 1)\) \((-2 : -1 : 1)\) \((-2 : 1 : 1)\) \((1 : -44 : 4)\) \((1 : 44 : 4)\)

magma: [C![-2,-1,1],C![-2,0,1],C![-1,-1,1],C![-1,0,1],C![0,-1,1],C![0,0,1],C![1,-54,4],C![1,-10,4],C![1,-1,1],C![1,0,0],C![1,0,1]]; // minimal model
 
magma: [C![-2,-1,1],C![-2,1,1],C![-1,-1,1],C![-1,1,1],C![0,-1,1],C![0,1,1],C![1,-44,4],C![1,44,4],C![1,-1,1],C![1,0,0],C![1,1,1]]; // simplified model
 

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: \(\Z \oplus \Z\)

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\((-1 : -1 : 1) + (0 : 0 : 1) - 2 \cdot(1 : 0 : 0)\) \(x (x + z)\) \(=\) \(0,\) \(y\) \(=\) \(xz^2\) \(0.206024\) \(\infty\)
\((0 : -1 : 1) - (1 : 0 : 0)\) \(x\) \(=\) \(0,\) \(y\) \(=\) \(-z^3\) \(0.102849\) \(\infty\)
Generator $D_0$ Height Order
\((-1 : -1 : 1) + (0 : 0 : 1) - 2 \cdot(1 : 0 : 0)\) \(x (x + z)\) \(=\) \(0,\) \(y\) \(=\) \(xz^2\) \(0.206024\) \(\infty\)
\((0 : -1 : 1) - (1 : 0 : 0)\) \(x\) \(=\) \(0,\) \(y\) \(=\) \(-z^3\) \(0.102849\) \(\infty\)
Generator $D_0$ Height Order
\((-1 : -1 : 1) + (0 : 1 : 1) - 2 \cdot(1 : 0 : 0)\) \(x (x + z)\) \(=\) \(0,\) \(y\) \(=\) \(2xz^2 + z^3\) \(0.206024\) \(\infty\)
\((0 : -1 : 1) - (1 : 0 : 0)\) \(x\) \(=\) \(0,\) \(y\) \(=\) \(-z^3\) \(0.102849\) \(\infty\)

2-torsion field: 5.5.207184.1

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(2\)
Mordell-Weil rank: \(2\)
2-Selmer rank:\(2\)
Regulator: \( 0.020630 \)
Real period: \( 23.28386 \)
Tamagawa product: \( 1 \)
Torsion order:\( 1 \)
Leading coefficient: \( 0.480366 \)
Analytic order of Ш: \( 1 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor Cluster picture
\(23\) \(1\) \(1\) \(1\) \(( 1 - T )( 1 + 5 T + 23 T^{2} )\)
\(563\) \(1\) \(1\) \(1\) \(( 1 - T )( 1 - 35 T + 563 T^{2} )\)

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?
\(2\) 2.6.1 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);