Properties

Label 4.4.18736.1-21.1-a2
Base field 4.4.18736.1
Conductor norm \( 21 \)
CM no
Base change no
Q-curve no
Torsion order \( 2 \)
Rank not available

Related objects

Downloads

Learn more

Show commands: Magma / PariGP / SageMath

Base field 4.4.18736.1

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

sage: R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([5, 4, -5, -2, 1]))
 
gp: K = nfinit(Polrev([5, 4, -5, -2, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![5, 4, -5, -2, 1]);
 

Weierstrass equation

\({y}^2+\left(a^{3}-2a^{2}-2a+2\right){x}{y}+\left(a^{3}-a^{2}-3a-1\right){y}={x}^{3}+\left(a^{3}-2a^{2}-3a+2\right){x}^{2}+\left(35a^{3}-109a^{2}-2a+35\right){x}+252a^{3}-868a^{2}+126a+573\)
sage: E = EllipticCurve([K([2,-2,-2,1]),K([2,-3,-2,1]),K([-1,-3,-1,1]),K([35,-2,-109,35]),K([573,126,-868,252])])
 
gp: E = ellinit([Polrev([2,-2,-2,1]),Polrev([2,-3,-2,1]),Polrev([-1,-3,-1,1]),Polrev([35,-2,-109,35]),Polrev([573,126,-868,252])], K);
 
magma: E := EllipticCurve([K![2,-2,-2,1],K![2,-3,-2,1],K![-1,-3,-1,1],K![35,-2,-109,35],K![573,126,-868,252]]);
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

Conductor: \((-2a^3+5a^2+6a-9)\) = \((-a+1)\cdot(a^2-a-2)\)
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: \((-7a^3+18a^2-15a-77)\) = \((-a+1)^{4}\cdot(a^2-a-2)^{6}\)
sage: E.discriminant()
 
gp: E.disc
 
magma: Discriminant(E);
 
Discriminant norm: \( -9529569 \) = \(-3^{4}\cdot7^{6}\)
sage: E.discriminant().norm()
 
gp: norm(E.disc)
 
magma: Norm(Discriminant(E));
 
j-invariant: \( -\frac{7160824368248177247534251}{9529569} a^{3} + \frac{3630803224952966312784116}{1361367} a^{2} - \frac{1190422705762490880799601}{3176523} a - \frac{23110477084613048835734003}{9529569} \)
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: \(0 \le r \le 1\)
Torsion structure: \(\Z/2\Z\)
sage: T = E.torsion_subgroup(); T.invariants()
 
gp: T = elltors(E); T[2]
 
magma: T,piT := TorsionSubgroup(E); Invariants(T);
 
Torsion generator: $\left(-a^{3} - a^{2} + \frac{19}{2} a + \frac{9}{4} : \frac{15}{8} a^{3} - \frac{15}{2} a^{2} + \frac{19}{4} a + \frac{29}{2} : 1\right)$
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: \(0 \le r \le 1\)
Regulator: not available
Period: \( 14.074176850634399653361638384874830984 \)
Tamagawa product: \( 12 \)  =  \(2\cdot( 2 \cdot 3 )\)
Torsion order: \(2\)
Leading coefficient: \( 3.41927045527000 \)
Analytic order of Ш: not available

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\((j)_{-}\)
\((-a+1)\) \(3\) \(2\) \(I_{4}\) Non-split multiplicative \(1\) \(1\) \(4\) \(4\)
\((a^2-a-2)\) \(7\) \(6\) \(I_{6}\) Split multiplicative \(-1\) \(1\) \(6\) \(6\)

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.
Its isogeny class 21.1-a consists of curves linked by isogenies of degree 2.

Base change

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

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