Minimal equation
Minimal equation
Simplified equation
$y^2 + (x^3 + 1)y = 2x^4 + x^3 - 2x^2 - x$ | (homogenize, simplify) |
$y^2 + (x^3 + z^3)y = 2x^4z^2 + x^3z^3 - 2x^2z^4 - xz^5$ | (dehomogenize, simplify) |
$y^2 = x^6 + 8x^4 + 6x^3 - 8x^2 - 4x + 1$ | (homogenize, minimize) |
sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([0, -1, -2, 1, 2]), R([1, 0, 0, 1]));
magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![0, -1, -2, 1, 2], R![1, 0, 0, 1]);
sage: X = HyperellipticCurve(R([1, -4, -8, 6, 8, 0, 1]))
magma: X,pi:= SimplifiedModel(C);
Invariants
Conductor: | \( N \) | \(=\) | \(164326\) | \(=\) | \( 2 \cdot 82163 \) | magma: Conductor(LSeries(C)); Factorization($1);
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Discriminant: | \( \Delta \) | \(=\) | \(-328652\) | \(=\) | \( - 2^{2} \cdot 82163 \) | magma: Discriminant(C); Factorization(Integers()!$1);
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Igusa-Clebsch invariants
Igusa invariants
G2 invariants
\( I_2 \) | \(=\) | \(500\) | \(=\) | \( 2^{2} \cdot 5^{3} \) |
\( I_4 \) | \(=\) | \(21049\) | \(=\) | \( 7 \cdot 31 \cdot 97 \) |
\( I_6 \) | \(=\) | \(1530861\) | \(=\) | \( 3 \cdot 510287 \) |
\( I_{10} \) | \(=\) | \(-42067456\) | \(=\) | \( - 2^{9} \cdot 82163 \) |
\( J_2 \) | \(=\) | \(125\) | \(=\) | \( 5^{3} \) |
\( J_4 \) | \(=\) | \(-226\) | \(=\) | \( - 2 \cdot 113 \) |
\( J_6 \) | \(=\) | \(13712\) | \(=\) | \( 2^{4} \cdot 857 \) |
\( J_8 \) | \(=\) | \(415731\) | \(=\) | \( 3 \cdot 138577 \) |
\( J_{10} \) | \(=\) | \(-328652\) | \(=\) | \( - 2^{2} \cdot 82163 \) |
\( g_1 \) | \(=\) | \(-30517578125/328652\) | ||
\( g_2 \) | \(=\) | \(220703125/164326\) | ||
\( g_3 \) | \(=\) | \(-53562500/82163\) |
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);
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\(\mathrm{Aut}(X_{\overline{\Q}})\) | \(\simeq\) | $C_2$ | magma: AutomorphismGroup(ChangeRing(C,AlgebraicClosure(Rationals()))); IdentifyGroup($1);
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Rational points
Known points | |||||
---|---|---|---|---|---|
\((1 : 0 : 0)\) | \((1 : -1 : 0)\) | \((0 : 0 : 1)\) | \((-1 : 0 : 1)\) | \((0 : -1 : 1)\) | \((1 : 0 : 1)\) |
\((-1 : 0 : 2)\) | \((1 : -2 : 1)\) | \((-2 : -2 : 1)\) | \((-3 : -4 : 1)\) | \((-1 : -7 : 2)\) | \((-2 : 9 : 1)\) |
\((-2 : -9 : 3)\) | \((-2 : -10 : 3)\) | \((-3 : 30 : 1)\) |
Known points | |||||
---|---|---|---|---|---|
\((1 : 0 : 0)\) | \((1 : -1 : 0)\) | \((0 : 0 : 1)\) | \((-1 : 0 : 1)\) | \((0 : -1 : 1)\) | \((1 : 0 : 1)\) |
\((-1 : 0 : 2)\) | \((1 : -2 : 1)\) | \((-2 : -2 : 1)\) | \((-3 : -4 : 1)\) | \((-1 : -7 : 2)\) | \((-2 : 9 : 1)\) |
\((-2 : -9 : 3)\) | \((-2 : -10 : 3)\) | \((-3 : 30 : 1)\) |
Known points | |||||
---|---|---|---|---|---|
\((1 : -1 : 0)\) | \((1 : 1 : 0)\) | \((-1 : 0 : 1)\) | \((0 : -1 : 1)\) | \((0 : 1 : 1)\) | \((1 : -2 : 1)\) |
\((1 : 2 : 1)\) | \((-2 : -1 : 3)\) | \((-2 : 1 : 3)\) | \((-1 : -7 : 2)\) | \((-1 : 7 : 2)\) | \((-2 : -11 : 1)\) |
\((-2 : 11 : 1)\) | \((-3 : -34 : 1)\) | \((-3 : 34 : 1)\) |
magma: [C![-3,-4,1],C![-3,30,1],C![-2,-10,3],C![-2,-9,3],C![-2,-2,1],C![-2,9,1],C![-1,-7,2],C![-1,0,1],C![-1,0,2],C![0,-1,1],C![0,0,1],C![1,-2,1],C![1,-1,0],C![1,0,0],C![1,0,1]]; // minimal model
magma: [C![-3,-34,1],C![-3,34,1],C![-2,-1,3],C![-2,1,3],C![-2,-11,1],C![-2,11,1],C![-1,-7,2],C![-1,0,1],C![-1,7,2],C![0,-1,1],C![0,1,1],C![1,-2,1],C![1,-1,0],C![1,1,0],C![1,2,1]]; // 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: \(\Z \oplus \Z \oplus \Z\)
magma: MordellWeilGroupGenus2(Jacobian(C));
Generator | $D_0$ | Height | Order | |||||
---|---|---|---|---|---|---|---|---|
\((-1 : 0 : 1) + (1 : -2 : 1) - (1 : -1 : 0) - (1 : 0 : 0)\) | \((x - z) (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(-xz^2 - z^3\) | \(0.603278\) | \(\infty\) |
\((-1 : 0 : 1) + (0 : -1 : 1) - (1 : -1 : 0) - (1 : 0 : 0)\) | \(x (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(-xz^2 - z^3\) | \(0.252206\) | \(\infty\) |
\((-1 : 0 : 1) - (1 : 0 : 0)\) | \(z (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(-x^3 - z^3\) | \(0.231945\) | \(\infty\) |
Generator | $D_0$ | Height | Order | |||||
---|---|---|---|---|---|---|---|---|
\((-1 : 0 : 1) + (1 : -2 : 1) - (1 : -1 : 0) - (1 : 0 : 0)\) | \((x - z) (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(-xz^2 - z^3\) | \(0.603278\) | \(\infty\) |
\((-1 : 0 : 1) + (0 : -1 : 1) - (1 : -1 : 0) - (1 : 0 : 0)\) | \(x (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(-xz^2 - z^3\) | \(0.252206\) | \(\infty\) |
\((-1 : 0 : 1) - (1 : 0 : 0)\) | \(z (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(-x^3 - z^3\) | \(0.231945\) | \(\infty\) |
Generator | $D_0$ | Height | Order | |||||
---|---|---|---|---|---|---|---|---|
\((-1 : 0 : 1) + (1 : -2 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) | \((x - z) (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(x^3 - 2xz^2 - z^3\) | \(0.603278\) | \(\infty\) |
\((-1 : 0 : 1) + (0 : -1 : 1) - (1 : -1 : 0) - (1 : 1 : 0)\) | \(x (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(x^3 - 2xz^2 - z^3\) | \(0.252206\) | \(\infty\) |
\((-1 : 0 : 1) - (1 : 1 : 0)\) | \(z (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(-x^3 - z^3\) | \(0.231945\) | \(\infty\) |
2-torsion field: 5.3.1314608.2
BSD invariants
Hasse-Weil conjecture: | unverified |
Analytic rank: | \(3\) (upper bound) |
Mordell-Weil rank: | \(3\) |
2-Selmer rank: | \(3\) |
Regulator: | \( 0.033198 \) |
Real period: | \( 16.73408 \) |
Tamagawa product: | \( 2 \) |
Torsion order: | \( 1 \) |
Leading coefficient: | \( 1.111093 \) |
Analytic order of Ш: | \( 1 \) (rounded) |
Order of Ш: | square |
Local invariants
Prime | ord(\(N\)) | ord(\(\Delta\)) | Tamagawa | L-factor | Cluster picture |
---|---|---|---|---|---|
\(2\) | \(1\) | \(2\) | \(2\) | \(( 1 + T )( 1 + T + 2 T^{2} )\) | |
\(82163\) | \(1\) | \(1\) | \(1\) | \(( 1 - T )( 1 - 42 T + 82163 T^{2} )\) |
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);