# Properties

 Label 961.a.961.2 Conductor 961 Discriminant -961 Sato-Tate group $G_{3,3}$ $$\End(J_{\overline{\Q}}) \otimes \R$$ $$\R \times \R$$ $$\End(J_{\overline{\Q}}) \otimes \Q$$ $$\mathrm{RM}$$ $$\overline{\Q}$$-simple yes $$\mathrm{GL}_2$$-type yes

# Related objects

Show commands for: Magma / SageMath

## Minimal equation

magma: R<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(R![-7, 12, -18, 12, -8, 2, -1], R![1, 1, 0, 1]);
sage: R.<x> = PolynomialRing(QQ); C = HyperellipticCurve(R([-7, 12, -18, 12, -8, 2, -1]), R([1, 1, 0, 1]))

$y^2 + (x^3 + x + 1)y = -x^6 + 2x^5 - 8x^4 + 12x^3 - 18x^2 + 12x - 7$

## Invariants

 magma: Conductor(LSeries(C)); Factorization($1); $$N$$ = $$961$$ = $$31^{2}$$ magma: Discriminant(C); Factorization(Integers()!$1); $$\Delta$$ = $$-961$$ = $$-1 \cdot 31^{2}$$

### G2 invariants

magma: G2Invariants(C);

 $$I_2$$ = $$-22520$$ = $$-1 \cdot 2^{3} \cdot 5 \cdot 563$$ $$I_4$$ = $$2014084$$ = $$2^{2} \cdot 41 \cdot 12281$$ $$I_6$$ = $$-14164636792$$ = $$-1 \cdot 2^{3} \cdot 8627 \cdot 205237$$ $$I_{10}$$ = $$-3936256$$ = $$-1 \cdot 2^{12} \cdot 31^{2}$$ $$J_2$$ = $$-2815$$ = $$-1 \cdot 5 \cdot 563$$ $$J_4$$ = $$309196$$ = $$2^{2} \cdot 17 \cdot 4547$$ $$J_6$$ = $$-43449708$$ = $$-1 \cdot 2^{2} \cdot 3 \cdot 331 \cdot 10939$$ $$J_8$$ = $$6677190401$$ = $$7 \cdot 953884343$$ $$J_{10}$$ = $$-961$$ = $$-1 \cdot 31^{2}$$ $$g_1$$ = $$176763257309509375/961$$ $$g_2$$ = $$6897140364776500/961$$ $$g_3$$ = $$344305262376300/961$$
Alternative geometric invariants: G2

## Automorphism group

 magma: AutomorphismGroup(C); IdentifyGroup($1); $$\mathrm{Aut}(X)$$ $$\simeq$$ $$C_2$$ (GAP id : [2,1]) magma: AutomorphismGroup(ChangeRing(C,AlgebraicClosure(Rationals()))); IdentifyGroup($1); $$\mathrm{Aut}(X_{\overline{\Q}})$$ $$\simeq$$ $$C_2$$ (GAP id : [2,1])

## Rational points

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);

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

magma: [];

There are no rational points.

magma: #Roots(HyperellipticPolynomials(SimplifiedModel(C)));

Number of rational Weierstrass points: $$0$$

## Invariants of the Jacobian:

Analytic rank: $$0$$

magma: TwoSelmerGroup(Jacobian(C)); NumberOfGenerators($1); 2-Selmer rank: $$1$$ magma: HasSquareSha(Jacobian(C)); Order of Ш*: twice a square Tamagawa numbers: 1 (p = 31) magma: TorsionSubgroup(Jacobian(SimplifiedModel(C))); AbelianInvariants($1);

Torsion: $$\Z/{5}\Z$$

### Sato-Tate group

 $$\mathrm{ST}$$ $$\simeq$$ $G_{3,3}$ $$\mathrm{ST}^0$$ $$\simeq$$ $$\mathrm{SU}(2)\times\mathrm{SU}(2)$$

### Decomposition

Simple over $$\overline{\Q}$$

### Endomorphisms

Of $$\GL_2$$-type over $$\Q$$

Endomorphism ring over $$\Q$$:
 $$\End (J_{})$$ $$\simeq$$ $$\Z [\sqrt{5}]$$ $$\End (J_{}) \otimes \Q$$ $$\simeq$$ $$\Q(\sqrt{5})$$ $$\End (J_{}) \otimes \R$$ $$\simeq$$ $$\R \times \R$$

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