Properties

Label 4.4.7225.1-16.1-a5
Base field \(\Q(\sqrt{5}, \sqrt{17})\)
Conductor norm \( 16 \)
CM no
Base change no
Q-curve yes
Torsion order \( 2 \)
Rank \( 0 \)

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Base field \(\Q(\sqrt{5}, \sqrt{17})\)

Generator \(a\), with minimal polynomial \( x^{4} - 11 x^{2} + 9 \); class number \(1\).

Copy content comment:Define the base number field
 
Copy content sage:R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([9, 0, -11, 0, 1]))
 
Copy content gp:K = nfinit(Polrev([9, 0, -11, 0, 1]));
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![9, 0, -11, 0, 1]);
 
Copy content oscar:Qx, x = polynomial_ring(QQ); K, a = number_field(Qx([9, 0, -11, 0, 1]))
 

Weierstrass equation

\({y}^2+a{x}{y}+\left(-\frac{1}{6}a^{3}+\frac{7}{3}a+\frac{3}{2}\right){y}={x}^{3}+\left(-\frac{1}{6}a^{3}+\frac{1}{2}a^{2}+\frac{5}{6}a-1\right){x}^{2}+\left(\frac{21}{2}a^{3}+25a^{2}-54a-\frac{135}{2}\right){x}-\frac{683}{6}a^{3}-\frac{651}{2}a^{2}+\frac{1531}{6}a+438\)
Copy content comment:Define the curve
 
Copy content sage:E = EllipticCurve([K([0,1,0,0]),K([-1,5/6,1/2,-1/6]),K([3/2,7/3,0,-1/6]),K([-135/2,-54,25,21/2]),K([438,1531/6,-651/2,-683/6])])
 
Copy content gp:E = ellinit([Polrev([0,1,0,0]),Polrev([-1,5/6,1/2,-1/6]),Polrev([3/2,7/3,0,-1/6]),Polrev([-135/2,-54,25,21/2]),Polrev([438,1531/6,-651/2,-683/6])], K);
 
Copy content magma:E := EllipticCurve([K![0,1,0,0],K![-1,5/6,1/2,-1/6],K![3/2,7/3,0,-1/6],K![-135/2,-54,25,21/2],K![438,1531/6,-651/2,-683/6]]);
 
Copy content oscar:E = elliptic_curve([K([0,1,0,0]),K([-1,5/6,1/2,-1/6]),K([3/2,7/3,0,-1/6]),K([-135/2,-54,25,21/2]),K([438,1531/6,-651/2,-683/6])])
 

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

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

Mordell-Weil generators

$P$$\hat{h}(P)$Order
$\left(\frac{23}{24} a^{3} + \frac{7}{8} a^{2} - \frac{175}{24} a - \frac{11}{2} : -\frac{17}{48} a^{3} - \frac{13}{8} a^{2} + \frac{19}{12} a + \frac{57}{16} : 1\right)$$0$$2$

Invariants

Conductor: $\frak{N}$ = \((2)\) = \((1/6a^3-1/2a^2-5/6a+2)\cdot(-1/6a^3-1/2a^2+5/6a+2)\)
Copy content comment:Compute the conductor
 
Copy content sage:E.conductor()
 
Copy content gp:ellglobalred(E)[1]
 
Copy content magma:Conductor(E);
 
Copy content oscar:conductor(E)
 
Conductor norm: $N(\frak{N})$ = \( 16 \) = \(4\cdot4\)
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));
 
Copy content oscar:norm(conductor(E))
 
Discriminant: $\Delta$ = $-4/3a^3+56/3a+28$
Discriminant ideal: $\frak{D}_{\mathrm{min}} = (\Delta)$ = \((-4/3a^3+56/3a+28)\) = \((1/6a^3-1/2a^2-5/6a+2)^{3}\cdot(-1/6a^3-1/2a^2+5/6a+2)^{6}\)
Copy content comment:Compute the discriminant
 
Copy content sage:E.discriminant()
 
Copy content gp:E.disc
 
Copy content magma:Discriminant(E);
 
Copy content oscar:discriminant(E)
 
Discriminant norm: $N(\frak{D}_{\mathrm{min}}) = N(\Delta)$ = \( 262144 \) = \(4^{3}\cdot4^{6}\)
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));
 
Copy content oscar:norm(discriminant(E))
 
j-invariant: $j$ = \( \frac{2134939673743248165}{128} a^{3} - \frac{2014355762928143019}{128} a^{2} - \frac{21583753823445138297}{128} a + \frac{2545584743833170707}{16} \)
Copy content comment:Compute the j-invariant
 
Copy content sage:E.j_invariant()
 
Copy content gp:E.j
 
Copy content magma:jInvariant(E);
 
Copy content oscar:j_invariant(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: $r_{\mathrm{an}}$= \( 0 \)
Copy content comment:Compute the Mordell-Weil rank
 
Copy content sage:E.rank()
 
Copy content magma:Rank(E);
 
Mordell-Weil rank: $r$ = \(0\)
Regulator: $\mathrm{Reg}(E/K)$ = \( 1 \)
Néron-Tate Regulator: $\mathrm{Reg}_{\mathrm{NT}}(E/K)$ = \( 1 \)
Global period: $\Omega(E/K)$ \( 200.97924934729210783361842191666967269 \)
Tamagawa product: $\prod_{\frak{p}}c_{\frak{p}}$= \( 2 \)  =  \(1\cdot2\)
Torsion order: $\#E(K)_{\mathrm{tor}}$= \(2\)
Special value: $L^{(r)}(E/K,1)/r!$ \( 1.18223087851348 \)
Analytic order of Ш: Ш${}_{\mathrm{an}}$= \( 1 \) (rounded)

BSD formula

$$\begin{aligned}1.182230879 \approx L(E/K,1) & \overset{?}{=} \frac{ \# ะจ(E/K) \cdot \Omega(E/K) \cdot \mathrm{Reg}_{\mathrm{NT}}(E/K) \cdot \prod_{\mathfrak{p}} c_{\mathfrak{p}} } { \#E(K)_{\mathrm{tor}}^2 \cdot \left|d_K\right|^{1/2} } \\ & \approx \frac{ 1 \cdot 200.979249 \cdot 1 \cdot 2 } { {2^2 \cdot 85.000000} } \\ & \approx 1.182230879 \end{aligned}$$

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 \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{N}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{D}_{\mathrm{min}}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathrm{den}(j))\)
\((1/6a^3-1/2a^2-5/6a+2)\) \(4\) \(1\) \(I_{3}\) Non-split multiplicative \(1\) \(1\) \(3\) \(3\)
\((-1/6a^3-1/2a^2+5/6a+2)\) \(4\) \(2\) \(I_{6}\) Non-split multiplicative \(1\) \(1\) \(6\) \(6\)

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
\(3\) 3B

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 3, 6, 9 and 18.
Its isogeny class 16.1-a consists of curves linked by isogenies of degrees dividing 18.

Base change

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

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