Genus 2 curve 7927.b.7927.1

• Label: 7927.b.7927.1
• Conductor: $7927$
• Discriminant: $-7927$
• Mordell-Weil group: \(\Z \oplus \Z\)
• 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

Minimal equation

$y^2 + x^3y = -2x^4 - x^3 + 3x^2 + x - 1$

(, )

Invariants

Conductor:	\( N \)	\(=\)	\(7927\)	\(=\)	\( 7927 \)
Discriminant:	\( \Delta \)	\(=\)	\(-7927\)	\(=\)	\( -7927 \)

Igusa-Clebsch invariants

\( I_2 \)	\(=\)	\(648\)	\(=\)	\( 2^{3} \cdot 3^{4} \)
\( I_4 \)	\(=\)	\(2388\)	\(=\)	\( 2^{2} \cdot 3 \cdot 199 \)
\( I_6 \)	\(=\)	\(522000\)	\(=\)	\( 2^{4} \cdot 3^{2} \cdot 5^{3} \cdot 29 \)
\( I_{10} \)	\(=\)	\(-31708\)	\(=\)	\( - 2^{2} \cdot 7927 \)

Automorphism group

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

Rational points

Known points
\((1 : 0 : 0)\)	\((1 : -1 : 0)\)	\((-1 : 0 : 1)\)	\((1 : 0 : 1)\)	\((-1 : 1 : 1)\)	\((1 : -1 : 1)\)
\((1 : 0 : 2)\)	\((1 : -1 : 2)\)	\((-2 : 3 : 1)\)	\((-2 : 5 : 1)\)

Number of rational Weierstrass points: \(0\)

This curve is locally solvable everywhere.

Mordell-Weil group of the Jacobian

Group structure: \(\Z \oplus \Z\)

Generator	$D_0$						Height	Order
\(D_0 - 2 \cdot(1 : -1 : 0)\)	\(z^2\)	\(=\)	\(0,\)	\(y\)	\(=\)	\(0\)	\(0.265853\)	\(\infty\)
\(D_0 - (1 : -1 : 0) - (1 : 0 : 0)\)	\(x^2 + xz - z^2\)	\(=\)	\(0,\)	\(y\)	\(=\)	\(-xz^2\)	\(0.069502\)	\(\infty\)

2-torsion field: 6.4.507328.1

BSD invariants

Hasse-Weil conjecture:	unverified
Analytic rank:	\(2\)
Mordell-Weil rank:	\(2\)
2-Selmer rank:	\(2\)
Regulator:	\( 0.018265 \)
Real period:	\( 21.11808 \)
Tamagawa product:	\( 1 \)
Torsion order:	\( 1 \)
Leading coefficient:	\( 0.385723 \)
Analytic order of Ш:	\( 1 \)   (rounded)
Order of Ш:	square

Local invariants

Prime	ord(\(N\))	ord(\(\Delta\))	Tamagawa	L-factor	Cluster picture
\(7927\)	\(1\)	\(1\)	\(1\)	\(( 1 + T )( 1 + 91 T + 7927 T^{2} )\)

Galois representations

The mod-$\ell$ Galois representation has maximal image \(\GSp(4,\F_\ell)\) for all primes \( \ell \) .

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 \(\Q\).