Properties

Label 2.0.4.1-87616.2-b1
Base field \(\Q(\sqrt{-1}) \)
Conductor norm \( 87616 \)
CM no
Base change no
Q-curve yes
Torsion order \( 1 \)
Rank \( 2 \)

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Base field \(\Q(\sqrt{-1}) \)

Generator \(i\), with minimal polynomial \( x^{2} + 1 \); class number \(1\).

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

Weierstrass equation

\({y}^2={x}^{3}+\left(-i-1\right){x}^{2}+\left(34i-6\right){x}-6i+68\)
Copy content comment:Define the curve
 
Copy content sage:E = EllipticCurve([K([0,0]),K([-1,-1]),K([0,0]),K([-6,34]),K([68,-6])])
 
Copy content gp:E = ellinit([Polrev([0,0]),Polrev([-1,-1]),Polrev([0,0]),Polrev([-6,34]),Polrev([68,-6])], K);
 
Copy content magma:E := EllipticCurve([K![0,0],K![-1,-1],K![0,0],K![-6,34],K![68,-6]]);
 

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

\(\Z \oplus \Z\)

Mordell-Weil generators

$P$$\hat{h}(P)$Order
$\left(-3 i - 13 : 47 i - 23 : 1\right)$$0.31179618850581900412136072845154260468$$\infty$
$\left(i : -i + 6 : 1\right)$$0.42479793536229764132142084121325122274$$\infty$

Invariants

Conductor: $\frak{N}$ = \((296)\) = \((i+1)^{6}\cdot(i+6)\cdot(i-6)\)
Copy content comment:Compute the conductor
 
Copy content sage:E.conductor()
 
Copy content gp:ellglobalred(E)[1]
 
Copy content magma:Conductor(E);
 
Conductor norm: $N(\frak{N})$ = \( 87616 \) = \(2^{6}\cdot37\cdot37\)
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: $\Delta$ = $1989120i-2559808$
Discriminant ideal: $\frak{D}_{\mathrm{min}} = (\Delta)$ = \((1989120i-2559808)\) = \((i+1)^{12}\cdot(i+6)\cdot(i-6)^{5}\)
Copy content comment:Compute the discriminant
 
Copy content sage:E.discriminant()
 
Copy content gp:E.disc
 
Copy content magma:Discriminant(E);
 
Discriminant norm: $N(\frak{D}_{\mathrm{min}}) = N(\Delta)$ = \( 10509215371264 \) = \(2^{12}\cdot37\cdot37^{5}\)
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: $j$ = \( -\frac{33742443520}{69343957} i + \frac{85490406912}{69343957} \)
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: $r_{\mathrm{an}}$= \( 2 \)
Copy content comment:Compute the Mordell-Weil rank
 
Copy content sage:E.rank()
 
Copy content magma:Rank(E);
 
Mordell-Weil rank: $r$ = \(2\)
Regulator: $\mathrm{Reg}(E/K)$ \( 0.11968098233848999253900751592494300580 \)
Néron-Tate Regulator: $\mathrm{Reg}_{\mathrm{NT}}(E/K)$ \( 0.478723929353959970156030063699772023200 \)
Global period: $\Omega(E/K)$ \( 2.2598757895596782851706531787593835102 \)
Tamagawa product: $\prod_{\frak{p}}c_{\frak{p}}$= \( 10 \)  =  \(2\cdot1\cdot5\)
Torsion order: $\#E(K)_{\mathrm{tor}}$= \(1\)
Special value: $L^{(r)}(E/K,1)/r!$ \( 5.4092830891494596784087806382962823114 \)
Analytic order of Ш: Ш${}_{\mathrm{an}}$= \( 1 \) (rounded)

BSD formula

$$\begin{aligned}5.409283089 \approx L^{(2)}(E/K,1)/2! & \overset{?}{=} \frac{ \# ะจ(E/K) \cdot \Omega(E/K) \cdot \mathrm{Reg}_{\mathrm{NT}}(E/K) \cdot \prod_{\mathfrak{p}} c_{\mathfrak{p}} } { \#E(K)_{\mathrm{tor}}^2 \cdot \left|d_K\right|^{1/2} } \\ & \approx \frac{ 1 \cdot 2.259876 \cdot 0.478724 \cdot 10 } { {1^2 \cdot 2.000000} } \\ & \approx 5.409283089 \end{aligned}$$

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 not semistable. There are 3 primes $\frak{p}$ of bad reduction.

$\mathfrak{p}$ $N(\mathfrak{p})$ Tamagawa number Kodaira symbol Reduction type Root number \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{N}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{D}_{\mathrm{min}}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathrm{den}(j))\)
\((i+1)\) \(2\) \(2\) \(I_{2}^{*}\) Additive \(-1\) \(6\) \(12\) \(0\)
\((i+6)\) \(37\) \(1\) \(I_{1}\) Split multiplicative \(-1\) \(1\) \(1\) \(1\)
\((i-6)\) \(37\) \(5\) \(I_{5}\) Split multiplicative \(-1\) \(1\) \(5\) \(5\)

Galois Representations

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

prime Image of Galois Representation
\(5\) 5B

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 5.
Its isogeny class 87616.2-b consists of curves linked by isogenies of degree 5.

Base change

This elliptic curve is a \(\Q\)-curve.

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