Properties

Label 4.4.9909.1-21.1-a5
Base field 4.4.9909.1
Conductor norm \( 21 \)
CM no
Base change no
Q-curve no
Torsion order \( 4 \)
Rank \( 1 \)

Related objects

Downloads

Learn more

Show commands: Magma / PariGP / SageMath

Base field 4.4.9909.1

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

sage: R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([3, -3, -6, 0, 1]))
 
gp: K = nfinit(Polrev([3, -3, -6, 0, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![3, -3, -6, 0, 1]);
 

Weierstrass equation

\({y}^2+{x}{y}+\left(a^{2}-2\right){y}={x}^{3}+a{x}^{2}+\left(-50a^{3}+60a^{2}+227a-123\right){x}+382a^{3}-462a^{2}-1736a+949\)
sage: E = EllipticCurve([K([1,0,0,0]),K([0,1,0,0]),K([-2,0,1,0]),K([-123,227,60,-50]),K([949,-1736,-462,382])])
 
gp: E = ellinit([Polrev([1,0,0,0]),Polrev([0,1,0,0]),Polrev([-2,0,1,0]),Polrev([-123,227,60,-50]),Polrev([949,-1736,-462,382])], K);
 
magma: E := EllipticCurve([K![1,0,0,0],K![0,1,0,0],K![-2,0,1,0],K![-123,227,60,-50],K![949,-1736,-462,382]]);
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

Conductor: \((a-3)\) = \((-a^3+a^2+4a)\cdot(a^3-a^2-4a+1)\)
sage: E.conductor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
Conductor norm: \( 21 \) = \(3\cdot7\)
sage: E.conductor().norm()
 
gp: idealnorm(ellglobalred(E)[1])
 
magma: Norm(Conductor(E));
 
Discriminant: \((-9a^3+9a^2+81a-18)\) = \((-a^3+a^2+4a)^{8}\cdot(a^3-a^2-4a+1)^{4}\)
sage: E.discriminant()
 
gp: E.disc
 
magma: Discriminant(E);
 
Discriminant norm: \( 15752961 \) = \(3^{8}\cdot7^{4}\)
sage: E.discriminant().norm()
 
gp: norm(E.disc)
 
magma: Norm(Discriminant(E));
 
j-invariant: \( -\frac{25780022}{21609} a^{3} - \frac{18946955}{21609} a^{2} + \frac{5547721}{2401} a - \frac{16556678}{21609} \)
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: \(1\)
Generator $\left(a^{3} - 4 a + 2 : 4 a^{3} - 9 a^{2} - 24 a + 15 : 1\right)$
Height \(1.0640843313305757325177113777707671830\)
Torsion structure: \(\Z/4\Z\)
sage: T = E.torsion_subgroup(); T.invariants()
 
gp: T = elltors(E); T[2]
 
magma: T,piT := TorsionSubgroup(E); Invariants(T);
 
Torsion generator: $\left(2 a^{3} - 2 a^{2} - 9 a + 5 : 3 a^{3} - 5 a^{2} - 15 a + 9 : 1\right)$
sage: T.gens()
 
gp: T[3]
 
magma: [piT(P) : P in Generators(T)];
 

BSD invariants

Analytic rank: \( 1 \)
sage: E.rank()
 
magma: Rank(E);
 
Mordell-Weil rank: \(1\)
Regulator: \( 1.0640843313305757325177113777707671830 \)
Period: \( 87.105030326823751242452985106402193751 \)
Tamagawa product: \( 16 \)  =  \(2^{3}\cdot2\)
Torsion order: \(4\)
Leading coefficient: \( 3.72446898122785 \)
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\((j)_{-}\)
\((-a^3+a^2+4a)\) \(3\) \(8\) \(I_{8}\) Split multiplicative \(-1\) \(1\) \(8\) \(8\)
\((a^3-a^2-4a+1)\) \(7\) \(2\) \(I_{4}\) Non-split multiplicative \(1\) \(1\) \(4\) \(4\)

Galois Representations

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

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

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 4 and 8.
Its isogeny class 21.1-a consists of curves linked by isogenies of degrees dividing 8.

Base change

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

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