Properties

Label 2.2.28.1-484.1-a1
Base field \(\Q(\sqrt{7}) \)
Conductor norm \( 484 \)
CM no
Base change yes
Q-curve yes
Torsion order \( 1 \)
Rank \( 2 \)

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Base field \(\Q(\sqrt{7}) \)

Generator \(a\), with minimal polynomial \( x^{2} - 7 \); class number \(1\).

Copy content comment:Define the base number field
 
Copy content sage:R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([-7, 0, 1]))
 
Copy content gp:K = nfinit(Polrev([-7, 0, 1]));
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![-7, 0, 1]);
 

Weierstrass equation

\({y}^2+\left(a+1\right){y}={x}^{3}-{x}^{2}+\left(-928a-2455\right){x}+25483a+67421\)
Copy content comment:Define the curve
 
Copy content sage:E = EllipticCurve([K([0,0]),K([-1,0]),K([1,1]),K([-2455,-928]),K([67421,25483])])
 
Copy content gp:E = ellinit([Polrev([0,0]),Polrev([-1,0]),Polrev([1,1]),Polrev([-2455,-928]),Polrev([67421,25483])], K);
 
Copy content magma:E := EllipticCurve([K![0,0],K![-1,0],K![1,1],K![-2455,-928],K![67421,25483]]);
 

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$$\hat{h}(P)$Order
$\left(-5 a - 13 : -94 a - 248 : 1\right)$$0.058354610084010663261859064455529226298$$\infty$
$\left(\frac{17}{2} a + 23 : \frac{43}{4} a + \frac{117}{4} : 1\right)$$1.3037077044891824503117519726304769770$$\infty$

Invariants

Conductor: $\frak{N}$ = \((22)\) = \((a+3)^{2}\cdot(11)\)
Copy content comment:Compute the conductor
 
Copy content sage:E.conductor()
 
Copy content gp:ellglobalred(E)[1]
 
Copy content magma:Conductor(E);
 
Conductor norm: $N(\frak{N})$ = \( 484 \) = \(2^{2}\cdot121\)
Copy content comment:Compute the norm of the conductor
 
Copy content sage:E.conductor().norm()
 
Copy content gp:idealnorm(K, ellglobalred(E)[1])
 
Copy content magma:Norm(Conductor(E));
 
Discriminant: $\Delta$ = $-5324$
Discriminant ideal: $\frak{D}_{\mathrm{min}} = (\Delta)$ = \((-5324)\) = \((a+3)^{4}\cdot(11)^{3}\)
Copy content comment:Compute the discriminant
 
Copy content sage:E.discriminant()
 
Copy content gp:E.disc
 
Copy content magma:Discriminant(E);
 
Discriminant norm: $N(\frak{D}_{\mathrm{min}}) = N(\Delta)$ = \( 28344976 \) = \(2^{4}\cdot121^{3}\)
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: $j$ = \( -\frac{199794688}{1331} \)
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: $\mathrm{Reg}(E/K)$ \( 0.076077354758986840060518638579239874525 \)
Néron-Tate Regulator: $\mathrm{Reg}_{\mathrm{NT}}(E/K)$ \( 0.3043094190359473602420745543169594981000 \)
Global period: $\Omega(E/K)$ \( 18.654683720674665700236212121357562263 \)
Tamagawa product: $\prod_{\frak{p}}c_{\frak{p}}$= \( 3 \)  =  \(1\cdot3\)
Torsion order: $\#E(K)_{\mathrm{tor}}$= \(1\)
Special value: $L^{(r)}(E/K,1)/r!$ \( 3.2184407931297431277840950481433153304 \)
Analytic order of Ш: Ш${}_{\mathrm{an}}$= \( 1 \) (rounded)

BSD formula

$$\begin{aligned}3.218440793 \approx L^{(2)}(E/K,1)/2! & \overset{?}{=} \frac{ \# ะจ(E/K) \cdot \Omega(E/K) \cdot \mathrm{Reg}_{\mathrm{NT}}(E/K) \cdot \prod_{\mathfrak{p}} c_{\mathfrak{p}} } { \#E(K)_{\mathrm{tor}}^2 \cdot \left|d_K\right|^{1/2} } \\ & \approx \frac{ 1 \cdot 18.654684 \cdot 0.304309 \cdot 3 } { {1^2 \cdot 5.291503} } \\ & \approx 3.218440793 \end{aligned}$$

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

$\mathfrak{p}$ $N(\mathfrak{p})$ Tamagawa number Kodaira symbol Reduction type Root number \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{N}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{D}_{\mathrm{min}}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathrm{den}(j))\)
\((a+3)\) \(2\) \(1\) \(IV\) Additive \(-1\) \(2\) \(4\) \(0\)
\((11)\) \(121\) \(3\) \(I_{3}\) 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

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 3.
Its isogeny class 484.1-a 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
\(\Q\) 176.a1
\(\Q\) 2156.a1