Properties

Label 16108.b.64432.1
Conductor $16108$
Discriminant $64432$
Mordell-Weil group \(\Z/{5}\Z\)
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

$y^2 + (x^2 + x)y = 2x^5 - 32x^4 + 55x^3 - 79x^2 + 49x - 25$ (homogenize, simplify)
$y^2 + (x^2z + xz^2)y = 2x^5z - 32x^4z^2 + 55x^3z^3 - 79x^2z^4 + 49xz^5 - 25z^6$ (dehomogenize, simplify)
$y^2 = 8x^5 - 127x^4 + 222x^3 - 315x^2 + 196x - 100$ (homogenize, minimize)

sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([-25, 49, -79, 55, -32, 2]), R([0, 1, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![-25, 49, -79, 55, -32, 2], R![0, 1, 1]);
 
sage: X = HyperellipticCurve(R([-100, 196, -315, 222, -127, 8]))
 
magma: X,pi:= SimplifiedModel(C);
 

Invariants

Conductor: \( N \)  \(=\)  \(16108\) \(=\) \( 2^{2} \cdot 4027 \)
magma: Conductor(LSeries(C)); Factorization($1);
 
Discriminant: \( \Delta \)  \(=\)  \(64432\) \(=\) \( 2^{4} \cdot 4027 \)
magma: Discriminant(C); Factorization(Integers()!$1);
 

Igusa-Clebsch invariants

Igusa invariants

G2 invariants

\( I_2 \)  \(=\) \(140828\) \(=\)  \( 2^{2} \cdot 17 \cdot 19 \cdot 109 \)
\( I_4 \)  \(=\) \(1269640849\) \(=\)  \( 26053 \cdot 48733 \)
\( I_6 \)  \(=\) \(44520371520391\) \(=\)  \( 13 \cdot 3424643963107 \)
\( I_{10} \)  \(=\) \(-8247296\) \(=\)  \( - 2^{11} \cdot 4027 \)
\( J_2 \)  \(=\) \(35207\) \(=\)  \( 17 \cdot 19 \cdot 109 \)
\( J_4 \)  \(=\) \(-1254500\) \(=\)  \( - 2^{2} \cdot 5^{3} \cdot 13 \cdot 193 \)
\( J_6 \)  \(=\) \(44515616\) \(=\)  \( 2^{5} \cdot 1391113 \)
\( J_8 \)  \(=\) \(-1627239372\) \(=\)  \( - 2^{2} \cdot 3 \cdot 11 \cdot 12327571 \)
\( J_{10} \)  \(=\) \(-64432\) \(=\)  \( - 2^{4} \cdot 4027 \)
\( g_1 \)  \(=\) \(-54093502359788249792807/64432\)
\( g_2 \)  \(=\) \(13686668079248773375/16108\)
\( g_3 \)  \(=\) \(-3448660520341874/4027\)

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

All points: \((1 : 0 : 0)\)
All points: \((1 : 0 : 0)\)
All points: \((1 : 0 : 0)\)

magma: [C![1,0,0]]; // minimal model
 
magma: [C![1,0,0]]; // 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: \(\Z/{5}\Z\)

magma: MordellWeilGroupGenus2(Jacobian(C));
 

Generator $D_0$ Height Order
\(D_0 - 2 \cdot(1 : 0 : 0)\) \(18x^2 - 16xz + 17z^2\) \(=\) \(0,\) \(54y\) \(=\) \(-50xz^2 + 25z^3\) \(0\) \(5\)
Generator $D_0$ Height Order
\(D_0 - 2 \cdot(1 : 0 : 0)\) \(18x^2 - 16xz + 17z^2\) \(=\) \(0,\) \(54y\) \(=\) \(-50xz^2 + 25z^3\) \(0\) \(5\)
Generator $D_0$ Height Order
\(D_0 - 2 \cdot(1 : 0 : 0)\) \(18x^2 - 16xz + 17z^2\) \(=\) \(0,\) \(54y\) \(=\) \(x^2z - 99xz^2 + 50z^3\) \(0\) \(5\)

2-torsion field: 5.1.257728.2

BSD invariants

Hasse-Weil conjecture: unverified
Analytic rank: \(0\)
Mordell-Weil rank: \(0\)
2-Selmer rank:\(0\)
Regulator: \( 1 \)
Real period: \( 1.145759 \)
Tamagawa product: \( 5 \)
Torsion order:\( 5 \)
Leading coefficient: \( 2.062366 \)
Analytic order of Ш: \( 9 \)   (rounded)
Order of Ш:square

Local invariants

Prime ord(\(N\)) ord(\(\Delta\)) Tamagawa L-factor Cluster picture
\(2\) \(2\) \(4\) \(5\) \(( 1 - T )^{2}\)
\(4027\) \(1\) \(1\) \(1\) \(( 1 + T )( 1 + 67 T + 4027 T^{2} )\)

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
\(3\) 3.80.2 no
\(5\) not computed yes

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);