Minimal equation
Minimal equation
Simplified equation
| $y^2 + x^3y = 2x^3 + 2$ | (homogenize, simplify) |
| $y^2 + x^3y = 2x^3z^3 + 2z^6$ | (dehomogenize, simplify) |
| $y^2 = x^6 + 8x^3 + 8$ | (homogenize, minimize) |
Invariants
| Conductor: | \( N \) | \(=\) | \(186624\) | \(=\) | \( 2^{8} \cdot 3^{6} \) |
|
| Discriminant: | \( \Delta \) | \(=\) | \(373248\) | \(=\) | \( 2^{9} \cdot 3^{6} \) |
|
Igusa-Clebsch invariants
Igusa invariants
G2 invariants
| \( I_2 \) | \(=\) | \(32\) | \(=\) | \( 2^{5} \) |
| \( I_4 \) | \(=\) | \(117\) | \(=\) | \( 3^{2} \cdot 13 \) |
| \( I_6 \) | \(=\) | \(879\) | \(=\) | \( 3 \cdot 293 \) |
| \( I_{10} \) | \(=\) | \(-6\) | \(=\) | \( - 2 \cdot 3 \) |
| \( J_2 \) | \(=\) | \(192\) | \(=\) | \( 2^{6} \cdot 3 \) |
| \( J_4 \) | \(=\) | \(-1272\) | \(=\) | \( - 2^{3} \cdot 3 \cdot 53 \) |
| \( J_6 \) | \(=\) | \(-2624\) | \(=\) | \( - 2^{6} \cdot 41 \) |
| \( J_8 \) | \(=\) | \(-530448\) | \(=\) | \( - 2^{4} \cdot 3 \cdot 43 \cdot 257 \) |
| \( J_{10} \) | \(=\) | \(-373248\) | \(=\) | \( - 2^{9} \cdot 3^{6} \) |
| \( g_1 \) | \(=\) | \(-2097152/3\) | ||
| \( g_2 \) | \(=\) | \(217088/9\) | ||
| \( g_3 \) | \(=\) | \(20992/81\) |
Automorphism group
| \(\mathrm{Aut}(X)\) | \(\simeq\) | $C_2$ |
|
| \(\mathrm{Aut}(X_{\overline{\Q}})\) | \(\simeq\) | $D_6$ |
|
Rational points
Number of rational Weierstrass points: \(0\)
This curve is locally solvable everywhere.
Mordell-Weil group of the Jacobian
Group structure: \(\Z \oplus \Z/{3}\Z\)
| Generator | $D_0$ | Height | Order | |||||
|---|---|---|---|---|---|---|---|---|
| \((-1 : 0 : 1) - (1 : -1 : 0)\) | \(z (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(0\) | \(0.721206\) | \(\infty\) |
| \(D_0 - 2 \cdot(1 : -1 : 0)\) | \(z^2\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(0\) | \(0\) | \(3\) |
| Generator | $D_0$ | Height | Order | |||||
|---|---|---|---|---|---|---|---|---|
| \((-1 : 0 : 1) - (1 : -1 : 0)\) | \(z (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(0\) | \(0.721206\) | \(\infty\) |
| \(D_0 - 2 \cdot(1 : -1 : 0)\) | \(z^2\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(0\) | \(0\) | \(3\) |
| Generator | $D_0$ | Height | Order | |||||
|---|---|---|---|---|---|---|---|---|
| \((-1 : -1 : 1) - (1 : -1 : 0)\) | \(z (x + z)\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(x^3\) | \(0.721206\) | \(\infty\) |
| \(D_0 - 2 \cdot(1 : -1 : 0)\) | \(z^2\) | \(=\) | \(0,\) | \(y\) | \(=\) | \(x^3\) | \(0\) | \(3\) |
BSD invariants
| Hasse-Weil conjecture: | unverified |
| Analytic rank: | \(1\) |
| Mordell-Weil rank: | \(1\) |
| 2-Selmer rank: | \(1\) |
| Regulator: | \( 0.721206 \) |
| Real period: | \( 11.73095 \) |
| Tamagawa product: | \( 3 \) |
| Torsion order: | \( 3 \) |
| Leading coefficient: | \( 2.820144 \) |
| Analytic order of Ш: | \( 1 \) (rounded) |
| Order of Ш: | square |
Local invariants
| Prime | ord(\(N\)) | ord(\(\Delta\)) | Tamagawa | Root number* | L-factor | Cluster picture | Tame reduction? |
|---|---|---|---|---|---|---|---|
| \(2\) | \(8\) | \(9\) | \(3\) | \(-1^*\) | \(1\) | no | |
| \(3\) | \(6\) | \(6\) | \(1\) | \(1^*\) | \(1\) | no |
Galois representations
For primes $\ell \ge 5$ the Galois representation data has not been computed for this curve since it is not generic.
For primes $\ell \le 3$, the image of the mod-$\ell$ Galois representation is listed in the table below, whenever it is not all of $\GSp(4,\F_\ell)$.
| Prime \(\ell\) | mod-\(\ell\) image | Is torsion prime? |
|---|---|---|
| \(2\) | 2.60.2 | no |
| \(3\) | 3.2880.5 | yes |
Sato-Tate group
| \(\mathrm{ST}\) | \(\simeq\) | $J(E_2)$ |
| \(\mathrm{ST}^0\) | \(\simeq\) | \(\mathrm{SU}(2)\) |
Decomposition of the Jacobian
Splits over the number field \(\Q (b) \simeq \) \(\Q(\sqrt{2}) \) with defining polynomial:
\(x^{2} - 2\)
Decomposes up to isogeny as the product of the non-isogenous elliptic curve isogeny classes:
Elliptic curve isogeny class 2.2.8.1-2916.1-c
Elliptic curve isogeny class 2.2.8.1-2916.1-b
Endomorphisms of the Jacobian
Not of \(\GL_2\)-type over \(\Q\)
Endomorphism ring over \(\Q\):
| \(\End (J_{})\) | \(\simeq\) | \(\Z\) |
| \(\End (J_{}) \otimes \Q \) | \(\simeq\) | \(\Q\) |
| \(\End (J_{}) \otimes \R\) | \(\simeq\) | \(\R\) |
Smallest field over which all endomorphisms are defined:
Galois number field \(K = \Q (a) \simeq \) \(\Q(\sqrt{2}, \sqrt{-3})\) with defining polynomial \(x^{4} + 2 x^{2} + 4\)
Not of \(\GL_2\)-type over \(\overline{\Q}\)
Endomorphism ring over \(\overline{\Q}\):
| \(\End (J_{\overline{\Q}})\) | \(\simeq\) | an Eichler order of index \(3\) in a maximal order of \(\End (J_{\overline{\Q}}) \otimes \Q\) |
| \(\End (J_{\overline{\Q}}) \otimes \Q \) | \(\simeq\) | \(\mathrm{M}_2(\)\(\Q\)\()\) |
| \(\End (J_{\overline{\Q}}) \otimes \R\) | \(\simeq\) | \(\mathrm{M}_2 (\R)\) |
Remainder of the endomorphism lattice by field
Over subfield \(F \simeq \) \(\Q(\sqrt{2}) \) with generator \(\frac{1}{2} a^{3}\) with minimal polynomial \(x^{2} - 2\):
| \(\End (J_{F})\) | \(\simeq\) | an order of index \(2\) in \(\Z \times \Z\) |
| \(\End (J_{F}) \otimes \Q \) | \(\simeq\) | \(\Q\) \(\times\) \(\Q\) |
| \(\End (J_{F}) \otimes \R\) | \(\simeq\) | \(\R \times \R\) |
Of \(\GL_2\)-type, not simple
Over subfield \(F \simeq \) \(\Q(\sqrt{-6}) \) with generator \(-\frac{1}{2} a^{3} - 2 a\) with minimal polynomial \(x^{2} + 6\):
| \(\End (J_{F})\) | \(\simeq\) | \(\Z [\sqrt{3}]\) |
| \(\End (J_{F}) \otimes \Q \) | \(\simeq\) | \(\Q(\sqrt{3}) \) |
| \(\End (J_{F}) \otimes \R\) | \(\simeq\) | \(\R \times \R\) |
Of \(\GL_2\)-type, simple
Over subfield \(F \simeq \) \(\Q(\sqrt{-3}) \) with generator \(-\frac{1}{2} a^{2}\) with minimal polynomial \(x^{2} - x + 1\):
| \(\End (J_{F})\) | \(\simeq\) | \(\Z [\frac{1 + \sqrt{-3}}{2}]\) |
| \(\End (J_{F}) \otimes \Q \) | \(\simeq\) | \(\Q(\sqrt{-3}) \) |
| \(\End (J_{F}) \otimes \R\) | \(\simeq\) | \(\C\) |
Of \(\GL_2\)-type, simple