# Properties

 Base field 4.4.19821.1 Label 4.4.19821.1-27.2-d2 Conductor $$(9,-\frac{1}{3} a^{3} + \frac{2}{3} a^{2} + 2 a - 1)$$ Conductor norm $$27$$ CM no base-change no Q-curve no Torsion order $$1$$ Rank not available

# Related objects

Show commands for: Magma / Pari/GP / SageMath

## Base field 4.4.19821.1

Generator $$a$$, with minimal polynomial $$x^{4} - x^{3} - 8 x^{2} + 6 x + 3$$; class number $$1$$.

sage: x = polygen(QQ); K.<a> = NumberField(x^4 - x^3 - 8*x^2 + 6*x + 3)

gp: K = nfinit(a^4 - a^3 - 8*a^2 + 6*a + 3);

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![3, 6, -8, -1, 1]);

## Weierstrass equation

$$y^2 + \left(\frac{1}{3} a^{3} + \frac{1}{3} a^{2} - 2 a\right) x y + a y = x^{3} + \left(-a^{2} + 5\right) x^{2} + \left(-a^{2} - a + 9\right) x + \frac{1}{3} a^{3} - \frac{2}{3} a^{2} - 2 a + 5$$
sage: E = EllipticCurve(K, [1/3*a^3 + 1/3*a^2 - 2*a, -a^2 + 5, a, -a^2 - a + 9, 1/3*a^3 - 2/3*a^2 - 2*a + 5])

gp: E = ellinit([1/3*a^3 + 1/3*a^2 - 2*a, -a^2 + 5, a, -a^2 - a + 9, 1/3*a^3 - 2/3*a^2 - 2*a + 5],K)

magma: E := ChangeRing(EllipticCurve([1/3*a^3 + 1/3*a^2 - 2*a, -a^2 + 5, a, -a^2 - a + 9, 1/3*a^3 - 2/3*a^2 - 2*a + 5]),K);

This is a global minimal model.

sage: E.is_global_minimal_model()

## Invariants

 $$\mathfrak{N}$$ = $$(9,-\frac{1}{3} a^{3} + \frac{2}{3} a^{2} + 2 a - 1)$$ = $$\left(-\frac{1}{3} a^{3} - \frac{1}{3} a^{2} + 3 a + 2\right)^{3}$$ sage: E.conductor()  magma: Conductor(E); $$N(\mathfrak{N})$$ = $$27$$ = $$3^{3}$$ sage: E.conductor().norm()  magma: Norm(Conductor(E)); $$\mathfrak{D}$$ = $$(243,81 a,\frac{1}{3} a^{3} + \frac{1}{3} a^{2} + 37 a + 211,-\frac{1}{3} a^{3} + \frac{2}{3} a^{2} + 35 a + 71)$$ = $$\left(-\frac{1}{3} a^{3} - \frac{1}{3} a^{2} + 3 a + 2\right)^{9}$$ sage: E.discriminant()  gp: E.disc  magma: Discriminant(E); $$N(\mathfrak{D})$$ = $$19683$$ = $$3^{9}$$ sage: E.discriminant().norm()  gp: norm(E.disc)  magma: Norm(Discriminant(E)); $$j$$ = $$\frac{18512}{3} a^{3} + \frac{1769}{3} a^{2} - 48583 a - 15892$$ sage: E.j_invariant()  gp: E.j  magma: jInvariant(E); $$\text{End} (E)$$ = $$\Z$$ (no Complex Multiplication ) sage: E.has_cm(), E.cm_discriminant()  magma: HasComplexMultiplication(E); $$\text{ST} (E)$$ = $\mathrm{SU}(2)$

## Mordell-Weil group

Rank not available.

sage: E.rank()

magma: Rank(E);

Regulator: not available

sage: gens = E.gens(); gens

magma: gens := [P:P in Generators(E)|Order(P) eq 0]; gens;

sage: E.regulator_of_points(gens)

magma: Regulator(gens);

## Torsion subgroup

Structure: Trivial sage: T = E.torsion_subgroup(); T.invariants()  gp: T = elltors(E); T[2]  magma: T,piT := TorsionSubgroup(E); Invariants(T);

## Local data at primes of bad reduction

sage: E.local_data()

magma: LocalInformation(E);

prime Norm Tamagawa number Kodaira symbol Reduction type Root number ord($$\mathfrak{N}$$) ord($$\mathfrak{D}$$) ord$$(j)_{-}$$
$$\left(-\frac{1}{3} a^{3} - \frac{1}{3} a^{2} + 3 a + 2\right)$$ $$3$$ $$1$$ $$IV^*$$ Additive $$1$$ $$3$$ $$9$$ $$0$$

## Galois Representations

The mod $$p$$ Galois Representation has maximal image for all primes $$p < 1000$$ except those listed.

prime Image of Galois Representation
$$3$$ 3B

## Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree $$d$$ for $$d=$$ 3.
Its isogeny class 27.2-d consists of curves linked by isogenies of degree 3.

## Base change

This curve is not the base-change of an elliptic curve defined over $$\Q$$. It is not a $$\Q$$-curve.