Properties

Base field 6.6.434581.1
Label 6.6.434581.1-71.2-a1
Conductor \((71,2 a^{4} - 4 a^{3} - 6 a^{2} + 7 a + 2)\)
Conductor norm \( 71 \)
CM no
base-change no
Q-curve no
Torsion order \( 2 \)
Rank not available

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Base field 6.6.434581.1

Generator \(a\), with minimal polynomial \( x^{6} - 2 x^{5} - 4 x^{4} + 5 x^{3} + 4 x^{2} - 2 x - 1 \); class number \(1\).

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![-1, -2, 4, 5, -4, -2, 1]);
sage: x = polygen(QQ); K.<a> = NumberField(x^6 - 2*x^5 - 4*x^4 + 5*x^3 + 4*x^2 - 2*x - 1)
gp (2.8): K = nfinit(a^6 - 2*a^5 - 4*a^4 + 5*a^3 + 4*a^2 - 2*a - 1);

Weierstrass equation

\( y^2 + a x y + \left(3 a^{5} - 7 a^{4} - 8 a^{3} + 15 a^{2} + a - 4\right) y = x^{3} + \left(-a^{5} + 2 a^{4} + 4 a^{3} - 4 a^{2} - 4 a + 2\right) x^{2} + \left(-5 a^{5} + 14 a^{4} + 8 a^{3} - 25 a^{2} + 6\right) x + a^{5} + a^{4} - 11 a^{3} - a^{2} + 18 a - 8 \)
magma: E := ChangeRing(EllipticCurve([a, -a^5 + 2*a^4 + 4*a^3 - 4*a^2 - 4*a + 2, 3*a^5 - 7*a^4 - 8*a^3 + 15*a^2 + a - 4, -5*a^5 + 14*a^4 + 8*a^3 - 25*a^2 + 6, a^5 + a^4 - 11*a^3 - a^2 + 18*a - 8]),K);
sage: E = EllipticCurve(K, [a, -a^5 + 2*a^4 + 4*a^3 - 4*a^2 - 4*a + 2, 3*a^5 - 7*a^4 - 8*a^3 + 15*a^2 + a - 4, -5*a^5 + 14*a^4 + 8*a^3 - 25*a^2 + 6, a^5 + a^4 - 11*a^3 - a^2 + 18*a - 8])
gp (2.8): E = ellinit([a, -a^5 + 2*a^4 + 4*a^3 - 4*a^2 - 4*a + 2, 3*a^5 - 7*a^4 - 8*a^3 + 15*a^2 + a - 4, -5*a^5 + 14*a^4 + 8*a^3 - 25*a^2 + 6, a^5 + a^4 - 11*a^3 - a^2 + 18*a - 8],K)

This is a global minimal model.

sage: E.is_global_minimal_model()

Invariants

\(\mathfrak{N} \) = \((71,2 a^{4} - 4 a^{3} - 6 a^{2} + 7 a + 2)\) = \( \left(a^{3} - 3 a\right) \)
magma: Conductor(E);
sage: E.conductor()
\(N(\mathfrak{N}) \) = \( 71 \) = \( 71 \)
magma: Norm(Conductor(E));
sage: E.conductor().norm()
\(\mathfrak{D}\) = \((71,a^{4} - 2 a^{3} - 3 a^{2} + 3 a + 58,a^{5} - 3 a^{4} - 2 a^{3} + 8 a^{2} + 16,a + 28,a^{5} - 2 a^{4} - 3 a^{3} + 3 a^{2} + a + 37,a^{5} - 2 a^{4} - 3 a^{3} + 4 a^{2} + 6)\) = \( \left(a^{3} - 3 a\right) \)
magma: Discriminant(E);
sage: E.discriminant()
gp (2.8): E.disc
\(N(\mathfrak{D})\) = \( 71 \) = \( 71 \)
magma: Norm(Discriminant(E));
sage: E.discriminant().norm()
gp (2.8): norm(E.disc)
\(j\) = \( -\frac{771436057367340}{71} a^{5} + \frac{1021204229550191}{71} a^{4} + \frac{3776605848171226}{71} a^{3} - \frac{1302945474751863}{71} a^{2} - \frac{3967265080250394}{71} a - \frac{1140546291203617}{71} \)
magma: jInvariant(E);
sage: E.j_invariant()
gp (2.8): E.j
\( \text{End} (E) \) = \(\Z\)   (no Complex Multiplication )
magma: HasComplexMultiplication(E);
sage: E.has_cm(), E.cm_discriminant()
\( \text{ST} (E) \) = $\mathrm{SU}(2)$

Mordell-Weil group

Rank not available.
magma: Rank(E);
sage: E.rank()
magma: Generators(E); // includes torsion
sage: E.gens()

Regulator: not available

magma: Regulator(Generators(E));
sage: E.regulator_of_points(E.gens())

Torsion subgroup

Structure: \(\Z/2\Z\)
magma: TorsionSubgroup(E);
sage: E.torsion_subgroup().gens()
gp (2.8): elltors(E)[2]
magma: Order(TorsionSubgroup(E));
sage: E.torsion_order()
gp (2.8): elltors(E)[1]
Generator: $\left(-2 a^{5} + 5 a^{4} + 5 a^{3} - 12 a^{2} - a + 3 : -2 a^{5} + 5 a^{4} + 5 a^{3} - 11 a^{2} + 3 : 1\right)$
magma: [f(P): P in Generators(T)] where T,f:=TorsionSubgroup(E);
sage: E.torsion_subgroup().gens()
gp (2.8): elltors(E)[3]

Local data at primes of bad reduction

magma: LocalInformation(E);
sage: E.local_data()
prime Norm Tamagawa number Kodaira symbol Reduction type Root number ord(\(\mathfrak{N}\)) ord(\(\mathfrak{D}\)) ord\((j)_{-}\)
\( \left(a^{3} - 3 a\right) \) \(71\) \(1\) \(I_{1}\) Non-split multiplicative \(1\) \(1\) \(1\) \(1\)

Galois Representations

The mod \( p \) Galois Representation has maximal image for all primes \( p \) except those listed.

prime Image of Galois Representation
\(2\) 2B
\(3\) 3B

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 3 and 6.
Its isogeny class 71.2-a consists of curves linked by isogenies of degrees dividing 6.

Base change

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