Properties

Label 4.4.2624.1-28.2-b2
Base field 4.4.2624.1
Conductor norm \( 28 \)
CM no
Base change no
Q-curve no
Torsion order \( 9 \)
Rank \( 0 \)

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Base field 4.4.2624.1

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

sage: R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([1, 2, -3, -2, 1]))
 
gp: K = nfinit(Polrev([1, 2, -3, -2, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 2, -3, -2, 1]);
 

Weierstrass equation

\({y}^2+\left(a^{2}-2a-1\right){x}{y}+{y}={x}^{3}\)
sage: E = EllipticCurve([K([-1,-2,1,0]),K([0,0,0,0]),K([1,0,0,0]),K([0,0,0,0]),K([0,0,0,0])])
 
gp: E = ellinit([Polrev([-1,-2,1,0]),Polrev([0,0,0,0]),Polrev([1,0,0,0]),Polrev([0,0,0,0]),Polrev([0,0,0,0])], K);
 
magma: E := EllipticCurve([K![-1,-2,1,0],K![0,0,0,0],K![1,0,0,0],K![0,0,0,0],K![0,0,0,0]]);
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

Conductor: \((a^3-2a^2-4a+1)\) = \((a^3-2a^2-2a+1)\cdot(-a^2+a+2)\)
sage: E.conductor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
Conductor norm: \( 28 \) = \(4\cdot7\)
sage: E.conductor().norm()
 
gp: idealnorm(ellglobalred(E)[1])
 
magma: Norm(Conductor(E));
 
Discriminant: \((-2a^3+10a^2-10a-32)\) = \((a^3-2a^2-2a+1)^{3}\cdot(-a^2+a+2)^{3}\)
sage: E.discriminant()
 
gp: E.disc
 
magma: Discriminant(E);
 
Discriminant norm: \( 21952 \) = \(4^{3}\cdot7^{3}\)
sage: E.discriminant().norm()
 
gp: norm(E.disc)
 
magma: Norm(Discriminant(E));
 
j-invariant: \( \frac{526254}{343} a^{3} - \frac{360229}{196} a^{2} - \frac{7989259}{1372} a - \frac{2455651}{1372} \)
sage: E.j_invariant()
 
gp: E.j
 
magma: jInvariant(E);
 
Endomorphism ring: \(\Z\)
Geometric endomorphism ring: \(\Z\) (no potential complex multiplication)
sage: E.has_cm(), E.cm_discriminant()
 
magma: HasComplexMultiplication(E);
 
Sato-Tate group: $\mathrm{SU}(2)$

Mordell-Weil group

Rank: \(0\)
Torsion structure: \(\Z/9\Z\)
sage: T = E.torsion_subgroup(); T.invariants()
 
gp: T = elltors(E); T[2]
 
magma: T,piT := TorsionSubgroup(E); Invariants(T);
 
Torsion generator: $\left(a + 1 : -a^{3} + 2 a^{2} + 4 a : 1\right)$
sage: T.gens()
 
gp: T[3]
 
magma: [piT(P) : P in Generators(T)];
 

BSD invariants

Analytic rank: \( 0 \)
sage: E.rank()
 
magma: Rank(E);
 
Mordell-Weil rank: \(0\)
Regulator: \( 1 \)
Period: \( 565.55822578808052469075546824942822093 \)
Tamagawa product: \( 9 \)  =  \(3\cdot3\)
Torsion order: \(9\)
Leading coefficient: \( 1.22674105122736 \)
Analytic order of Ш: \( 1 \) (rounded)

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\((j)_{-}\)
\((a^3-2a^2-2a+1)\) \(4\) \(3\) \(I_{3}\) Split multiplicative \(-1\) \(1\) \(3\) \(3\)
\((-a^2+a+2)\) \(7\) \(3\) \(I_{3}\) Split multiplicative \(-1\) \(1\) \(3\) \(3\)

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.1.1

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 3 and 9.
Its isogeny class 28.2-b consists of curves linked by isogenies of degrees dividing 9.

Base change

This elliptic curve is not a \(\Q\)-curve.

It is not the base change of an elliptic curve defined over any subfield.