Properties

Label 4.4.9909.1-16.1-b2
Base field 4.4.9909.1
Conductor norm \( 16 \)
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

\({y}^2+\left(a^{3}-a^{2}-4a+2\right){x}{y}+\left(a^{2}-a-2\right){y}={x}^{3}+\left(a^{2}-4\right){x}^{2}+\left(-17a^{3}+20a^{2}+78a-38\right){x}-523a^{3}+632a^{2}+2376a-1303\)
Copy content comment:Define the curve
 
Copy content sage:E = EllipticCurve([K([2,-4,-1,1]),K([-4,0,1,0]),K([-2,-1,1,0]),K([-38,78,20,-17]),K([-1303,2376,632,-523])])
 
Copy content gp:E = ellinit([Polrev([2,-4,-1,1]),Polrev([-4,0,1,0]),Polrev([-2,-1,1,0]),Polrev([-38,78,20,-17]),Polrev([-1303,2376,632,-523])], K);
 
Copy content magma:E := EllipticCurve([K![2,-4,-1,1],K![-4,0,1,0],K![-2,-1,1,0],K![-38,78,20,-17],K![-1303,2376,632,-523]]);
 

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$$\hat{h}(P)$Order
$\left(23 a^{3} - 28 a^{2} - 105 a + 59 : 197 a^{3} - 238 a^{2} - 895 a + 491 : 1\right)$$0.77052452050244519876326259506224478952$$\infty$
$\left(3 a^{3} - 4 a^{2} - 14 a + 9 : -6 a^{3} + 7 a^{2} + 28 a - 14 : 1\right)$$0$$2$

Invariants

Conductor: $\frak{N}$ = \((2)\) = \((2)\)
Copy content comment:Compute the conductor
 
Copy content sage:E.conductor()
 
Copy content gp:ellglobalred(E)[1]
 
Copy content magma:Conductor(E);
 
Conductor norm: $N(\frak{N})$ = \( 16 \) = \(16\)
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: $\Delta$ = $4$
Discriminant ideal: $\frak{D}_{\mathrm{min}} = (\Delta)$ = \((4)\) = \((2)^{2}\)
Copy content comment:Compute the discriminant
 
Copy content sage:E.discriminant()
 
Copy content gp:E.disc
 
Copy content magma:Discriminant(E);
 
Discriminant norm: $N(\frak{D}_{\mathrm{min}}) = N(\Delta)$ = \( 256 \) = \(16^{2}\)
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: $j$ = \( \frac{622203}{2} a^{3} - \frac{2391861}{4} a^{2} - \frac{3043377}{4} a + \frac{2003589}{4} \)
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: $\mathrm{Reg}(E/K)$ \( 0.77052452050244519876326259506224478952 \)
Néron-Tate Regulator: $\mathrm{Reg}_{\mathrm{NT}}(E/K)$ \( 3.08209808200978079505305038024897915808 \)
Global period: $\Omega(E/K)$ \( 201.29920476477767425269159146176453386 \)
Tamagawa product: $\prod_{\frak{p}}c_{\frak{p}}$= \( 2 \)
Torsion order: $\#E(K)_{\mathrm{tor}}$= \(2\)
Special value: $L^{(r)}(E/K,1)/r!$ \( 3.11633117697007 \)
Analytic order of Ш: Ш${}_{\mathrm{an}}$= \( 1 \) (rounded)

BSD formula

$$\begin{aligned}3.116331177 \approx L'(E/K,1) & \overset{?}{=} \frac{ \# ะจ(E/K) \cdot \Omega(E/K) \cdot \mathrm{Reg}_{\mathrm{NT}}(E/K) \cdot \prod_{\mathfrak{p}} c_{\mathfrak{p}} } { \#E(K)_{\mathrm{tor}}^2 \cdot \left|d_K\right|^{1/2} } \\ & \approx \frac{ 1 \cdot 201.299205 \cdot 3.082098 \cdot 2 } { {2^2 \cdot 99.543960} } \\ & \approx 3.116331177 \end{aligned}$$

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 is only one prime $\frak{p}$ of bad reduction.

$\mathfrak{p}$ $N(\mathfrak{p})$ Tamagawa number Kodaira symbol Reduction type Root number \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{N}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{D}_{\mathrm{min}}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathrm{den}(j))\)
\((2)\) \(16\) \(2\) \(I_{2}\) Split multiplicative \(-1\) \(1\) \(2\) \(2\)

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 16.1-b 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.