Properties

Label 4.4.9909.1-21.1-d3
Base field 4.4.9909.1
Conductor norm \( 21 \)
CM no
Base change no
Q-curve no
Torsion order \( 2 \)
Rank \( 1 \)

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Base field 4.4.9909.1

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

Copy content comment:Define the base number field
 
Copy content sage:R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([3, -3, -6, 0, 1]))
 
Copy content gp:K = nfinit(Polrev([3, -3, -6, 0, 1]));
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![3, -3, -6, 0, 1]);
 

Weierstrass equation

\({y}^2+\left(a^{3}-a^{2}-3a+2\right){x}{y}+\left(a+1\right){y}={x}^{3}+\left(a^{3}-a^{2}-5a\right){x}^{2}+\left(-84a^{3}+146a^{2}+299a-174\right){x}-188a^{3}+858a^{2}+1498a-961\)
Copy content comment:Define the curve
 
Copy content sage:E = EllipticCurve([K([2,-3,-1,1]),K([0,-5,-1,1]),K([1,1,0,0]),K([-174,299,146,-84]),K([-961,1498,858,-188])])
 
Copy content gp:E = ellinit([Polrev([2,-3,-1,1]),Polrev([0,-5,-1,1]),Polrev([1,1,0,0]),Polrev([-174,299,146,-84]),Polrev([-961,1498,858,-188])], K);
 
Copy content magma:E := EllipticCurve([K![2,-3,-1,1],K![0,-5,-1,1],K![1,1,0,0],K![-174,299,146,-84],K![-961,1498,858,-188]]);
 

This is a global minimal model.

Copy content comment:Test whether it is a global minimal model
 
Copy content sage:E.is_global_minimal_model()
 

Mordell-Weil group structure

\(\Z \oplus \Z/{2}\Z\)

Mordell-Weil generators

$P$$\hat{h}(P)$Order
$\left(\frac{2468608}{621075} a^{3} - \frac{5032882}{621075} a^{2} - \frac{759858}{41405} a + \frac{4240877}{207025} : -\frac{2293749282}{94196375} a^{3} + \frac{2929287028}{94196375} a^{2} + \frac{6141520538}{56517825} a - \frac{8340027949}{94196375} : 1\right)$$6.6182378136884860742154484345434523973$$\infty$
$\left(\frac{11}{4} a^{3} - \frac{11}{2} a^{2} - \frac{57}{4} a + \frac{39}{4} : -\frac{19}{8} a^{3} + 7 a^{2} + \frac{67}{4} a - 11 : 1\right)$$0$$2$

Invariants

Conductor: $\frak{N}$ = \((a-3)\) = \((-a^3+a^2+4a)\cdot(a^3-a^2-4a+1)\)
Copy content comment:Compute the conductor
 
Copy content sage:E.conductor()
 
Copy content gp:ellglobalred(E)[1]
 
Copy content magma:Conductor(E);
 
Conductor norm: $N(\frak{N})$ = \( 21 \) = \(3\cdot7\)
Copy content comment:Compute the norm of the conductor
 
Copy content sage:E.conductor().norm()
 
Copy content gp:idealnorm(ellglobalred(E)[1])
 
Copy content magma:Norm(Conductor(E));
 
Discriminant: $\Delta$ = $-7703906a^3+9164061a^2+34244423a-23060691$
Discriminant ideal: $\frak{D}_{\mathrm{min}} = (\Delta)$ = \((-7703906a^3+9164061a^2+34244423a-23060691)\) = \((-a^3+a^2+4a)\cdot(a^3-a^2-4a+1)^{32}\)
Copy content comment:Compute the discriminant
 
Copy content sage:E.discriminant()
 
Copy content gp:E.disc
 
Copy content magma:Discriminant(E);
 
Discriminant norm: $N(\frak{D}_{\mathrm{min}}) = N(\Delta)$ = \( 3313283022731761938915897603 \) = \(3\cdot7^{32}\)
Copy content comment:Compute the norm of the discriminant
 
Copy content sage:E.discriminant().norm()
 
Copy content gp:norm(E.disc)
 
Copy content magma:Norm(Discriminant(E));
 
j-invariant: $j$ = \( -\frac{8726799587448504883954432291309058}{3313283022731761938915897603} a^{3} + \frac{3512609295216958802166282509619697}{1104427674243920646305299201} a^{2} + \frac{13211649577996599292098856645855219}{1104427674243920646305299201} a - \frac{7226027092698629340082787287567899}{1104427674243920646305299201} \)
Copy content comment:Compute the j-invariant
 
Copy content sage:E.j_invariant()
 
Copy content gp:E.j
 
Copy content magma:jInvariant(E);
 
Endomorphism ring: $\mathrm{End}(E)$ = \(\Z\)   
Geometric endomorphism ring: $\mathrm{End}(E_{\overline{\Q}})$ = \(\Z\)    (no potential complex multiplication)
Copy content comment:Test for Complex Multiplication
 
Copy content sage:E.has_cm(), E.cm_discriminant()
 
Copy content magma:HasComplexMultiplication(E);
 
Sato-Tate group: $\mathrm{ST}(E)$ = $\mathrm{SU}(2)$

BSD invariants

Analytic rank: $r_{\mathrm{an}}$= \( 1 \)
Copy content comment:Compute the Mordell-Weil rank
 
Copy content sage:E.rank()
 
Copy content magma:Rank(E);
 
Mordell-Weil rank: $r$ = \(1\)
Regulator: $\mathrm{Reg}(E/K)$ \( 6.6182378136884860742154484345434523973 \)
Néron-Tate Regulator: $\mathrm{Reg}_{\mathrm{NT}}(E/K)$ \( 26.472951254753944296861793738173809589 \)
Global period: $\Omega(E/K)$ \( 1.3802803304060593042144664110623292779 \)
Tamagawa product: $\prod_{\frak{p}}c_{\frak{p}}$= \( 2 \)  =  \(1\cdot2\)
Torsion order: $\#E(K)_{\mathrm{tor}}$= \(2\)
Special value: $L^{(r)}(E/K,1)/r!$ \( 2.93659957703088 \)
Analytic order of Ш: Ш${}_{\mathrm{an}}$= \( 16 \) (rounded)

BSD formula

$$\begin{aligned}2.936599577 \approx L'(E/K,1) & \overset{?}{=} \frac{ \# ะจ(E/K) \cdot \Omega(E/K) \cdot \mathrm{Reg}_{\mathrm{NT}}(E/K) \cdot \prod_{\mathfrak{p}} c_{\mathfrak{p}} } { \#E(K)_{\mathrm{tor}}^2 \cdot \left|d_K\right|^{1/2} } \\ & \approx \frac{ 16 \cdot 1.380280 \cdot 26.472951 \cdot 2 } { {2^2 \cdot 99.543960} } \\ & \approx 2.936599577 \end{aligned}$$

Local data at primes of bad reduction

Copy content comment:Compute the local reduction data at primes of bad reduction
 
Copy content sage:E.local_data()
 
Copy content magma:LocalInformation(E);
 

This elliptic curve is semistable. There are 2 primes $\frak{p}$ of bad reduction.

$\mathfrak{p}$ $N(\mathfrak{p})$ Tamagawa number Kodaira symbol Reduction type Root number \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{N}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{D}_{\mathrm{min}}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathrm{den}(j))\)
\((-a^3+a^2+4a)\) \(3\) \(1\) \(I_{1}\) Split multiplicative \(-1\) \(1\) \(1\) \(1\)
\((a^3-a^2-4a+1)\) \(7\) \(2\) \(I_{32}\) Non-split multiplicative \(1\) \(1\) \(32\) \(32\)

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-d 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.