Properties

Label 4.4.12400.1-20.2-d2
Base field 4.4.12400.1
Conductor norm \( 20 \)
CM no
Base change no
Q-curve no
Torsion order \( 2 \)
Rank \( 1 \)

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Base field 4.4.12400.1

Generator \(a\), with minimal polynomial \( x^{4} - 12 x^{2} + 31 \); class number \(1\).

sage: R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([31, 0, -12, 0, 1]))
 
gp: K = nfinit(Polrev([31, 0, -12, 0, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![31, 0, -12, 0, 1]);
 

Weierstrass equation

\({y}^2+\left(\frac{1}{2}a^{3}-\frac{7}{2}a+1\right){x}{y}+\left(\frac{1}{2}a^{3}-\frac{5}{2}a+1\right){y}={x}^{3}+\left(\frac{1}{2}a^{3}-\frac{1}{2}a^{2}-\frac{7}{2}a+\frac{7}{2}\right){x}^{2}+\left(-106a^{3}-280a^{2}+421a+1009\right){x}+1829a^{3}+\frac{10915}{2}a^{2}-6690a-\frac{41841}{2}\)
sage: E = EllipticCurve([K([1,-7/2,0,1/2]),K([7/2,-7/2,-1/2,1/2]),K([1,-5/2,0,1/2]),K([1009,421,-280,-106]),K([-41841/2,-6690,10915/2,1829])])
 
gp: E = ellinit([Polrev([1,-7/2,0,1/2]),Polrev([7/2,-7/2,-1/2,1/2]),Polrev([1,-5/2,0,1/2]),Polrev([1009,421,-280,-106]),Polrev([-41841/2,-6690,10915/2,1829])], K);
 
magma: E := EllipticCurve([K![1,-7/2,0,1/2],K![7/2,-7/2,-1/2,1/2],K![1,-5/2,0,1/2],K![1009,421,-280,-106],K![-41841/2,-6690,10915/2,1829]]);
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

Conductor: \((-1/2a^3+1/2a^2+7/2a-7/2)\) = \((-a+3)\cdot(-1/2a^3-3/2a^2+3/2a+11/2)\)
sage: E.conductor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
Conductor norm: \( 20 \) = \(4\cdot5\)
sage: E.conductor().norm()
 
gp: idealnorm(ellglobalred(E)[1])
 
magma: Norm(Conductor(E));
 
Discriminant: \((100a^3-176a^2+12a-816)\) = \((-a+3)^{6}\cdot(-1/2a^3-3/2a^2+3/2a+11/2)^{12}\)
sage: E.discriminant()
 
gp: E.disc
 
magma: Discriminant(E);
 
Discriminant norm: \( 1000000000000 \) = \(4^{6}\cdot5^{12}\)
sage: E.discriminant().norm()
 
gp: norm(E.disc)
 
magma: Norm(Discriminant(E));
 
j-invariant: \( \frac{2028817931053}{250000} a^{3} + \frac{3032952547803}{125000} a^{2} - \frac{7629088540237}{250000} a - \frac{1142292115229}{12500} \)
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 $\left(-\frac{7}{2} a^{3} - 9 a^{2} + \frac{67}{2} a + 89 : -66 a^{3} - \frac{215}{2} a^{2} + 536 a + \frac{1731}{2} : 1\right)$
Height \(0.50398168699254402461364858193911517982\)
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: $\left(\frac{3}{2} a^{3} + 2 a^{2} - \frac{15}{2} a - 2 : -3 a^{3} - \frac{5}{2} a^{2} + 17 a + \frac{1}{2} : 1\right)$
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: \(1\)
Regulator: \( 0.50398168699254402461364858193911517982 \)
Period: \( 22.841198040814572663103017098452791424 \)
Tamagawa product: \( 24 \)  =  \(2\cdot( 2^{2} \cdot 3 )\)
Torsion order: \(2\)
Leading coefficient: \( 2.48104153222950 \)
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\((j)_{-}\)
\((-a+3)\) \(4\) \(2\) \(I_{6}\) Non-split multiplicative \(1\) \(1\) \(6\) \(6\)
\((-1/2a^3-3/2a^2+3/2a+11/2)\) \(5\) \(12\) \(I_{12}\) Split multiplicative \(-1\) \(1\) \(12\) \(12\)

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
\(3\) 3B

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 3 and 6.
Its isogeny class 20.2-d consists of curves linked by isogenies of degrees dividing 6.

Base change

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

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