Properties

Label 2.2.5.1-2420.1-e1
Base field \(\Q(\sqrt{5}) \)
Conductor norm \( 2420 \)
CM no
Base change yes
Q-curve yes
Torsion order \( 3 \)
Rank \( 1 \)

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Base field \(\Q(\sqrt{5}) \)

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

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

Weierstrass equation

\({y}^2+{x}{y}+{y}={x}^{3}-89{x}+316\)
Copy content comment:Define the curve
 
Copy content sage:E = EllipticCurve([K([1,0]),K([0,0]),K([1,0]),K([-89,0]),K([316,0])])
 
Copy content gp:E = ellinit([Polrev([1,0]),Polrev([0,0]),Polrev([1,0]),Polrev([-89,0]),Polrev([316,0])], K);
 
Copy content magma:E := EllipticCurve([K![1,0],K![0,0],K![1,0],K![-89,0],K![316,0]]);
 

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

\(\Z \oplus \Z/{3}\Z\)

Mordell-Weil generators

$P$$\hat{h}(P)$Order
$\left(-2 \phi + 9 : -8 \phi + 12 : 1\right)$$0.021400148006828586228189049877086540462$$\infty$
$\left(4 : -8 : 1\right)$$0$$3$

Invariants

Conductor: $\frak{N}$ = \((-44\phi+22)\) = \((2)\cdot(-2\phi+1)\cdot(-3\phi+2)\cdot(-3\phi+1)\)
Copy content comment:Compute the conductor
 
Copy content sage:E.conductor()
 
Copy content gp:ellglobalred(E)[1]
 
Copy content magma:Conductor(E);
 
Conductor norm: $N(\frak{N})$ = \( 2420 \) = \(4\cdot5\cdot11\cdot11\)
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: $\Delta$ = $-851840$
Discriminant ideal: $\frak{D}_{\mathrm{min}} = (\Delta)$ = \((-851840)\) = \((2)^{7}\cdot(-2\phi+1)^{2}\cdot(-3\phi+2)^{3}\cdot(-3\phi+1)^{3}\)
Copy content comment:Compute the discriminant
 
Copy content sage:E.discriminant()
 
Copy content gp:E.disc
 
Copy content magma:Discriminant(E);
 
Discriminant norm: $N(\frak{D}_{\mathrm{min}}) = N(\Delta)$ = \( 725631385600 \) = \(4^{7}\cdot5^{2}\cdot11^{3}\cdot11^{3}\)
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: $j$ = \( -\frac{76711450249}{851840} \)
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: $\mathrm{Reg}(E/K)$ \( 0.021400148006828586228189049877086540462 \)
Néron-Tate Regulator: $\mathrm{Reg}_{\mathrm{NT}}(E/K)$ \( 0.04280029601365717245637809975417308092400 \)
Global period: $\Omega(E/K)$ \( 7.9872589102658578316211610028269686409 \)
Tamagawa product: $\prod_{\frak{p}}c_{\frak{p}}$= \( 126 \)  =  \(7\cdot2\cdot3\cdot3\)
Torsion order: $\#E(K)_{\mathrm{tor}}$= \(3\)
Special value: $L^{(r)}(E/K,1)/r!$ \( 2.1403636597447062604173358269264410705 \)
Analytic order of Ш: Ш${}_{\mathrm{an}}$= \( 1 \) (rounded)

BSD formula

$$\begin{aligned}2.140363660 \approx L'(E/K,1) & \overset{?}{=} \frac{ \# ะจ(E/K) \cdot \Omega(E/K) \cdot \mathrm{Reg}_{\mathrm{NT}}(E/K) \cdot \prod_{\mathfrak{p}} c_{\mathfrak{p}} } { \#E(K)_{\mathrm{tor}}^2 \cdot \left|d_K\right|^{1/2} } \\ & \approx \frac{ 1 \cdot 7.987259 \cdot 0.042800 \cdot 126 } { {3^2 \cdot 2.236068} } \\ & \approx 2.140363660 \end{aligned}$$

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 4 primes $\frak{p}$ of bad reduction.

$\mathfrak{p}$ $N(\mathfrak{p})$ Tamagawa number Kodaira symbol Reduction type Root number \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{N}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{D}_{\mathrm{min}}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathrm{den}(j))\)
\((2)\) \(4\) \(7\) \(I_{7}\) Split multiplicative \(-1\) \(1\) \(7\) \(7\)
\((-2\phi+1)\) \(5\) \(2\) \(I_{2}\) Non-split multiplicative \(1\) \(1\) \(2\) \(2\)
\((-3\phi+2)\) \(11\) \(3\) \(I_{3}\) Split multiplicative \(-1\) \(1\) \(3\) \(3\)
\((-3\phi+1)\) \(11\) \(3\) \(I_{3}\) Split multiplicative \(-1\) \(1\) \(3\) \(3\)

Galois Representations

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

prime Image of Galois Representation
\(3\) 3B.1.1

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 3.
Its isogeny class 2420.1-e consists of curves linked by isogenies of degree 3.

Base change

This elliptic curve is a \(\Q\)-curve. It is the base change of the following 2 elliptic curves:

Base field Curve
\(\Q\) 110.a1
\(\Q\) 550.i1