# Properties

 Label 832.a.832.1 Conductor 832 Discriminant -832 Sato-Tate group $\mathrm{USp}(4)$ $$\End(J_{\overline{\Q}}) \otimes \R$$ $$\R$$ $$\End(J_{\overline{\Q}}) \otimes \Q$$ $$\Q$$ $$\overline{\Q}$$-simple yes $$\mathrm{GL}_2$$-type no

# Related objects

Show commands for: Magma / SageMath

## Minimal equation

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

$y^2 + (x^3 + x)y = x^5 - x^3 + x^2 + 2x - 1$

## Invariants

 magma: Conductor(LSeries(C)); Factorization($1); $$N$$ = $$832$$ = $$2^{6} \cdot 13$$ magma: Discriminant(C); Factorization(Integers()!$1); $$\Delta$$ = $$-832$$ = $$-1 \cdot 2^{6} \cdot 13$$

### G2 invariants

magma: G2Invariants(C);

 $$I_2$$ = $$2176$$ = $$2^{7} \cdot 17$$ $$I_4$$ = $$-8384$$ = $$-1 \cdot 2^{6} \cdot 131$$ $$I_6$$ = $$-6349824$$ = $$-1 \cdot 2^{10} \cdot 3^{2} \cdot 13 \cdot 53$$ $$I_{10}$$ = $$-3407872$$ = $$-1 \cdot 2^{18} \cdot 13$$ $$J_2$$ = $$272$$ = $$2^{4} \cdot 17$$ $$J_4$$ = $$3170$$ = $$2 \cdot 5 \cdot 317$$ $$J_6$$ = $$51008$$ = $$2^{6} \cdot 797$$ $$J_8$$ = $$956319$$ = $$3 \cdot 7 \cdot 13 \cdot 31 \cdot 113$$ $$J_{10}$$ = $$-832$$ = $$-1 \cdot 2^{6} \cdot 13$$ $$g_1$$ = $$-23262937088/13$$ $$g_2$$ = $$-996749440/13$$ $$g_3$$ = $$-58965248/13$$
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 everywhere.

magma: [C![-2,5,1],C![1,-1,0],C![1,0,0]];

All rational points: (-2 : 5 : 1), (1 : -1 : 0), (1 : 0 : 0)

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

Number of rational Weierstrass points: $$1$$

## Invariants of the Jacobian:

Analytic rank: $$0$$

magma: TwoSelmerGroup(Jacobian(C)); NumberOfGenerators($1); 2-Selmer rank: $$1$$ magma: HasSquareSha(Jacobian(C)); Order of Ш*: square Tamagawa numbers: 1 (p = 2), 1 (p = 13) magma: TorsionSubgroup(Jacobian(SimplifiedModel(C))); AbelianInvariants($1);

Torsion: $$\Z/{8}\Z$$

### Sato-Tate group

 $$\mathrm{ST}$$ $$\simeq$$ $\mathrm{USp}(4)$ $$\mathrm{ST}^0$$ $$\simeq$$ $$\mathrm{USp}(4)$$

### Decomposition

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

### Endomorphisms

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 $$\Q$$.