Genus 2 curve 847.d.847.1

• Label: 847.d.847.1
• Conductor: $847$
• Discriminant: $-847$
• Mordell-Weil group: \(\Z/{3}\Z\)
• Sato-Tate group: $\mathrm{SU}(2)\times\mathrm{SU}(2)$
• \(\End(J_{\overline{\Q}}) \otimes \R\): \(\R \times \R\)
• \(\End(J_{\overline{\Q}}) \otimes \Q\): \(\Q \times \Q\)
• \(\End(J) \otimes \Q\): \(\Q \times \Q\)
• \(\overline{\Q}\)-simple: no
• \(\mathrm{GL}_2\)-type: yes

Minimal equation

$y^2 + (x^3 + x^2 + x + 1)y = -12x^6 - 15x^5 + 9x^4 + 31x^3 + 9x^2 - 15x - 12$

(, )

Invariants

Conductor:	\( N \)	\(=\)	\(847\)	\(=\)	\( 7 \cdot 11^{2} \)
Discriminant:	\( \Delta \)	\(=\)	\(-847\)	\(=\)	\( - 7 \cdot 11^{2} \)

Igusa-Clebsch invariants

\( I_2 \)	\(=\)	\(80408\)	\(=\)	\( 2^{3} \cdot 19 \cdot 23^{2} \)
\( I_4 \)	\(=\)	\(402403732\)	\(=\)	\( 2^{2} \cdot 2441 \cdot 41213 \)
\( I_6 \)	\(=\)	\(8094753026048\)	\(=\)	\( 2^{12} \cdot 13 \cdot 67 \cdot 499 \cdot 4547 \)
\( I_{10} \)	\(=\)	\(3388\)	\(=\)	\( 2^{2} \cdot 7 \cdot 11^{2} \)

Automorphism group

\(\mathrm{Aut}(X)\)	\(\simeq\)	$C_2^2$
\(\mathrm{Aut}(X_{\overline{\Q}})\)	\(\simeq\)	$C_2^2$

Rational points

This curve has no rational points.

Number of rational Weierstrass points: \(0\)

This curve is locally solvable except over $\R$.

Mordell-Weil group of the Jacobian

Group structure: \(\Z/{3}\Z\)

Generator	$D_0$						Height	Order
\(D_0 - D_\infty\)	\(18x^2 + 29xz + 18z^2\)	\(=\)	\(0,\)	\(162y\)	\(=\)	\(-77xz^2 - 126z^3\)	\(0\)	\(3\)

2-torsion field: 6.0.54208.1

BSD invariants

Hasse-Weil conjecture:	verified
Analytic rank:	\(0\)
Mordell-Weil rank:	\(0\)
2-Selmer rank:	\(1\)
Regulator:	\( 1 \)
Real period:	\( 1.179534 \)
Tamagawa product:	\( 1 \)
Torsion order:	\( 3 \)
Leading coefficient:	\( 0.262118 \)
Analytic order of Ш:	\( 2 \)   (rounded)
Order of Ш:	twice a square

Local invariants

Prime	ord(\(N\))	ord(\(\Delta\))	Tamagawa	L-factor	Cluster picture
\(7\)	\(1\)	\(1\)	\(1\)	\(( 1 - T )( 1 + 2 T + 7 T^{2} )\)
\(11\)	\(2\)	\(2\)	\(1\)	\(( 1 - T )( 1 + T )\)

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?
\(2\)	2.15.2	no
\(3\)	3.720.4	yes

Sato-Tate group

\(\mathrm{ST}\)	\(\simeq\)	$\mathrm{SU}(2)\times\mathrm{SU}(2)$
\(\mathrm{ST}^0\)	\(\simeq\)	\(\mathrm{SU}(2)\times\mathrm{SU}(2)\)

Decomposition of the Jacobian

Splits over \(\Q\)

Decomposes up to isogeny as the product of the non-isogenous elliptic curve isogeny classes:
  Elliptic curve isogeny class 77.b
  Elliptic curve isogeny class 11.a

Endomorphisms of the Jacobian

Of \(\GL_2\)-type over \(\Q\)

Endomorphism ring over \(\Q\):

\(\End (J_{})\)	\(\simeq\)	an order of index \(2\) in \(\Z \times \Z\)
\(\End (J_{}) \otimes \Q \)	\(\simeq\)	\(\Q\) \(\times\) \(\Q\)
\(\End (J_{}) \otimes \R\)	\(\simeq\)	\(\R \times \R\)

All \(\overline{\Q}\)-endomorphisms of the Jacobian are defined over \(\Q\).