Minimal equation
Minimal equation
Simplified equation
$y^2 + (x^3 + x)y = x^4 - 2x^3 + 2x^2 - 2x$ | (homogenize, simplify) |
$y^2 + (x^3 + xz^2)y = x^4z^2 - 2x^3z^3 + 2x^2z^4 - 2xz^5$ | (dehomogenize, simplify) |
$y^2 = x^6 + 6x^4 - 8x^3 + 9x^2 - 8x$ | (minimize, homogenize) |
sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([0, -2, 2, -2, 1]), R([0, 1, 0, 1]));
magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![0, -2, 2, -2, 1], R![0, 1, 0, 1]);
sage: X = HyperellipticCurve(R([0, -8, 9, -8, 6, 0, 1]))
magma: X,pi:= SimplifiedModel(C);
Invariants
Conductor: | \( N \) | \(=\) | \(4312\) | \(=\) | \( 2^{3} \cdot 7^{2} \cdot 11 \) | magma: Conductor(LSeries(C)); Factorization($1);
|
Discriminant: | \( \Delta \) | \(=\) | \(551936\) | \(=\) | \( 2^{10} \cdot 7^{2} \cdot 11 \) | magma: Discriminant(C); Factorization(Integers()!$1);
|
Igusa-Clebsch invariants
Igusa invariants
G2 invariants
\( I_2 \) | \(=\) | \(60\) | \(=\) | \( 2^{2} \cdot 3 \cdot 5 \) |
\( I_4 \) | \(=\) | \(477\) | \(=\) | \( 3^{2} \cdot 53 \) |
\( I_6 \) | \(=\) | \(-8865\) | \(=\) | \( - 3^{2} \cdot 5 \cdot 197 \) |
\( I_{10} \) | \(=\) | \(-68992\) | \(=\) | \( - 2^{7} \cdot 7^{2} \cdot 11 \) |
\( J_2 \) | \(=\) | \(60\) | \(=\) | \( 2^{2} \cdot 3 \cdot 5 \) |
\( J_4 \) | \(=\) | \(-168\) | \(=\) | \( - 2^{3} \cdot 3 \cdot 7 \) |
\( J_6 \) | \(=\) | \(13680\) | \(=\) | \( 2^{4} \cdot 3^{2} \cdot 5 \cdot 19 \) |
\( J_8 \) | \(=\) | \(198144\) | \(=\) | \( 2^{9} \cdot 3^{2} \cdot 43 \) |
\( J_{10} \) | \(=\) | \(-551936\) | \(=\) | \( - 2^{10} \cdot 7^{2} \cdot 11 \) |
\( g_1 \) | \(=\) | \(-759375/539\) | ||
\( g_2 \) | \(=\) | \(10125/154\) | ||
\( g_3 \) | \(=\) | \(-192375/2156\) |
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: \((1 : 0 : 0),\, (1 : -1 : 0),\, (0 : 0 : 1),\, (1 : -1 : 1)\)
magma: [C![0,0,1],C![1,-1,0],C![1,-1,1],C![1,0,0]]; // minimal model
magma: [C![0,0,1],C![1,-1,0],C![1,0,1],C![1,1,0]]; // simplified model
Number of rational Weierstrass points: \(2\)
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: \(\Z/{10}\Z\)
magma: MordellWeilGroupGenus2(Jacobian(C));
Generator | $D_0$ | Height | Order | |||||
---|---|---|---|---|---|---|---|---|
\((0 : 0 : 1) - (1 : -1 : 0)\) | \(z x\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(0\) | \(0\) | \(10\) |
Generator | $D_0$ | Height | Order | |||||
---|---|---|---|---|---|---|---|---|
\((0 : 0 : 1) - (1 : -1 : 0)\) | \(z x\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(0\) | \(0\) | \(10\) |
Generator | $D_0$ | Height | Order | |||||
---|---|---|---|---|---|---|---|---|
\((0 : 0 : 1) - (1 : -1 : 0)\) | \(z x\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(x^3 + xz^2\) | \(0\) | \(10\) |
BSD invariants
Hasse-Weil conjecture: | unverified |
Analytic rank: | \(0\) |
Mordell-Weil rank: | \(0\) |
2-Selmer rank: | \(1\) |
Regulator: | \( 1 \) |
Real period: | \( 10.28259 \) |
Tamagawa product: | \( 10 \) |
Torsion order: | \( 10 \) |
Leading coefficient: | \( 1.028259 \) |
Analytic order of Ш: | \( 1 \) (rounded) |
Order of Ш: | square |
Local invariants
Prime | ord(\(N\)) | ord(\(\Delta\)) | Tamagawa | L-factor | Cluster picture |
---|---|---|---|---|---|
\(2\) | \(3\) | \(10\) | \(10\) | \(1 - T\) | |
\(7\) | \(2\) | \(2\) | \(1\) | \(1 + T^{2}\) | |
\(11\) | \(1\) | \(1\) | \(1\) | \(( 1 + T )( 1 - 2 T + 11 T^{2} )\) |
Galois representations
For primes $\ell \le 3$, the image of the mod-$\ell$ Galois representation is listed in the table below, whenever it is not the maximal image $\GSp(4,\F_\ell)$
Prime \(\ell\) | mod-\(\ell\) image |
---|---|
\(2\) | 2.90.3 |
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 \(\Q\).