Properties

Label 4.4.16609.1-6.1-c4
Base field 4.4.16609.1
Conductor norm \( 6 \)
CM no
Base change no
Q-curve no
Torsion order \( 4 \)
Rank \( 1 \)

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Base field 4.4.16609.1

Generator \(a\), with minimal polynomial \( x^{4} - 7 x^{2} - x + 9 \); class number \(1\).

Copy content comment:Define the base number field
 
Copy content sage:R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([9, -1, -7, 0, 1]))
 
Copy content gp:K = nfinit(Polrev([9, -1, -7, 0, 1]));
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![9, -1, -7, 0, 1]);
 
Copy content oscar:Qx, x = polynomial_ring(QQ); K, a = number_field(Qx([9, -1, -7, 0, 1]))
 

Weierstrass equation

\({y}^2+\left(a^{3}-4a\right){x}{y}={x}^{3}+\left(a^{3}-2a^{2}-5a+7\right){x}^{2}+\left(-a^{3}+2a^{2}+5a-8\right){x}\)
Copy content comment:Define the curve
 
Copy content sage:E = EllipticCurve([K([0,-4,0,1]),K([7,-5,-2,1]),K([0,0,0,0]),K([-8,5,2,-1]),K([0,0,0,0])])
 
Copy content gp:E = ellinit([Polrev([0,-4,0,1]),Polrev([7,-5,-2,1]),Polrev([0,0,0,0]),Polrev([-8,5,2,-1]),Polrev([0,0,0,0])], K);
 
Copy content magma:E := EllipticCurve([K![0,-4,0,1],K![7,-5,-2,1],K![0,0,0,0],K![-8,5,2,-1],K![0,0,0,0]]);
 
Copy content oscar:E = elliptic_curve([K([0,-4,0,1]),K([7,-5,-2,1]),K([0,0,0,0]),K([-8,5,2,-1]),K([0,0,0,0])])
 

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

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

Mordell-Weil generators

$P$$\hat{h}(P)$Order
$\left(-a + 1 : -a^{3} + 2 a^{2} + 6 a - 9 : 1\right)$$0.037059618271888281783304914709362206675$$\infty$
$\left(0 : 0 : 1\right)$$0$$2$
$\left(-\frac{1}{4} a^{2} - \frac{1}{4} a + 1 : -\frac{1}{8} a^{3} + \frac{1}{2} a^{2} + a - \frac{9}{8} : 1\right)$$0$$2$

Invariants

Conductor: $\frak{N}$ = \((-a^2+3)\) = \((-a^2-a+2)\cdot(a^2-a-3)\)
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: $N(\frak{N})$ = \( 6 \) = \(2\cdot3\)
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: $\Delta$ = $-a^3-5a^2-2a+18$
Discriminant ideal: $\frak{D}_{\mathrm{min}} = (\Delta)$ = \((-a^3-5a^2-2a+18)\) = \((-a^2-a+2)^{2}\cdot(a^2-a-3)^{8}\)
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: $N(\frak{D}_{\mathrm{min}}) = N(\Delta)$ = \( 26244 \) = \(2^{2}\cdot3^{8}\)
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: $j$ = \( -\frac{97259155}{26244} a^{3} + \frac{20327771}{2916} a^{2} + \frac{14950541}{13122} a + \frac{319978897}{26244} \)
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: $r_{\mathrm{an}}$= \( 1 \)
Copy content comment:Compute the Mordell-Weil rank
 
Copy content sage:E.rank()
 
Copy content magma:Rank(E);
 
Mordell-Weil rank: $r$ = \(1\)
Regulator: $\mathrm{Reg}(E/K)$ \( 0.037059618271888281783304914709362206675 \)
Néron-Tate Regulator: $\mathrm{Reg}_{\mathrm{NT}}(E/K)$ \( 0.1482384730875531271332196588374488267000 \)
Global period: $\Omega(E/K)$ \( 1884.2593555684747412859868479522958511 \)
Tamagawa product: $\prod_{\frak{p}}c_{\frak{p}}$= \( 16 \)  =  \(2\cdot2^{3}\)
Torsion order: $\#E(K)_{\mathrm{tor}}$= \(4\)
Special value: $L^{(r)}(E/K,1)/r!$ \( 2.16735409488020 \)
Analytic order of Ш: Ш${}_{\mathrm{an}}$= \( 1 \) (rounded)

BSD formula

$$\begin{aligned}2.167354095 \approx L'(E/K,1) & \overset{?}{=} \frac{ \# ะจ(E/K) \cdot \Omega(E/K) \cdot \mathrm{Reg}_{\mathrm{NT}}(E/K) \cdot \prod_{\mathfrak{p}} c_{\mathfrak{p}} } { \#E(K)_{\mathrm{tor}}^2 \cdot \left|d_K\right|^{1/2} } \\ & \approx \frac{ 1 \cdot 1884.259356 \cdot 0.148238 \cdot 16 } { {4^2 \cdot 128.875909} } \\ & \approx 2.167354095 \end{aligned}$$

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 \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{N}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{D}_{\mathrm{min}}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathrm{den}(j))\)
\((-a^2-a+2)\) \(2\) \(2\) \(I_{2}\) Non-split multiplicative \(1\) \(1\) \(2\) \(2\)
\((a^2-a-3)\) \(3\) \(8\) \(I_{8}\) Split multiplicative \(-1\) \(1\) \(8\) \(8\)

Galois Representations

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

prime Image of Galois Representation
\(2\) 2Cs

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2 and 4.
Its isogeny class 6.1-c consists of curves linked by isogenies of degrees dividing 8.

Base change

This elliptic curve is not a \(\Q\)-curve.

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