Properties

Label 4.4.13625.1-4.2-b1
Base field 4.4.13625.1
Conductor norm \( 4 \)
CM no
Base change no
Q-curve no
Torsion order \( 8 \)
Rank \( 1 \)

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Base field 4.4.13625.1

Generator \(a\), with minimal polynomial \( x^{4} - 2 x^{3} - 11 x^{2} + 12 x + 31 \); class number \(1\).

Copy content comment:Define the base number field
 
Copy content sage:R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([31, 12, -11, -2, 1]))
 
Copy content gp:K = nfinit(Polrev([31, 12, -11, -2, 1]));
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![31, 12, -11, -2, 1]);
 
Copy content oscar:Qx, x = polynomial_ring(QQ); K, a = number_field(Qx([31, 12, -11, -2, 1]))
 

Weierstrass equation

\({y}^2+\left(\frac{1}{2}a^{3}-4a-\frac{7}{2}\right){x}{y}+\left(\frac{1}{2}a^{3}-3a-\frac{7}{2}\right){y}={x}^{3}+\left(-\frac{1}{2}a^{3}+a^{2}+2a-\frac{7}{2}\right){x}^{2}+\left(\frac{1}{2}a^{3}+2a^{2}-2a-\frac{7}{2}\right){x}-4a^{3}-\frac{9}{2}a^{2}+\frac{55}{2}a+\frac{75}{2}\)
Copy content comment:Define the curve
 
Copy content sage:E = EllipticCurve([K([-7/2,-4,0,1/2]),K([-7/2,2,1,-1/2]),K([-7/2,-3,0,1/2]),K([-7/2,-2,2,1/2]),K([75/2,55/2,-9/2,-4])])
 
Copy content gp:E = ellinit([Polrev([-7/2,-4,0,1/2]),Polrev([-7/2,2,1,-1/2]),Polrev([-7/2,-3,0,1/2]),Polrev([-7/2,-2,2,1/2]),Polrev([75/2,55/2,-9/2,-4])], K);
 
Copy content magma:E := EllipticCurve([K![-7/2,-4,0,1/2],K![-7/2,2,1,-1/2],K![-7/2,-3,0,1/2],K![-7/2,-2,2,1/2],K![75/2,55/2,-9/2,-4]]);
 
Copy content oscar:E = elliptic_curve([K([-7/2,-4,0,1/2]),K([-7/2,2,1,-1/2]),K([-7/2,-3,0,1/2]),K([-7/2,-2,2,1/2]),K([75/2,55/2,-9/2,-4])])
 

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

\(\Z \oplus \Z/{8}\Z\)

Mordell-Weil generators

$P$$\hat{h}(P)$Order
$\left(\frac{5}{2} a^{3} - 4 a^{2} - 15 a + \frac{41}{2} : -\frac{9}{2} a^{3} + 30 a^{2} + 23 a - \frac{363}{2} : 1\right)$$0.55290560099697775742505983416534392941$$\infty$
$\left(\frac{3}{2} a^{3} + \frac{3}{2} a^{2} - \frac{19}{2} a - 12 : \frac{11}{2} a^{3} + \frac{15}{2} a^{2} - \frac{71}{2} a - 51 : 1\right)$$0$$8$

Invariants

Conductor: $\frak{N}$ = \((1/2a^3-3/2a^2-5/2a+6)\) = \((1/2a^3-3/2a^2-5/2a+6)\)
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: $N(\frak{N})$ = \( 4 \) = \(4\)
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: $\Delta$ = $-9/2a^3+14a^2+21a-129/2$
Discriminant ideal: $\frak{D}_{\mathrm{min}} = (\Delta)$ = \((-9/2a^3+14a^2+21a-129/2)\) = \((1/2a^3-3/2a^2-5/2a+6)^{8}\)
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: $N(\frak{D}_{\mathrm{min}}) = N(\Delta)$ = \( 65536 \) = \(4^{8}\)
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: $j$ = \( -\frac{123165}{512} a^{3} + \frac{131307}{256} a^{2} + \frac{369921}{256} a + \frac{105115}{512} \)
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: $\mathrm{Reg}(E/K)$ \( 0.55290560099697775742505983416534392941 \)
Néron-Tate Regulator: $\mathrm{Reg}_{\mathrm{NT}}(E/K)$ \( 2.21162240398791102970023933666137571764 \)
Global period: $\Omega(E/K)$ \( 713.53159130117649670636356812462591988 \)
Tamagawa product: $\prod_{\frak{p}}c_{\frak{p}}$= \( 8 \)
Torsion order: $\#E(K)_{\mathrm{tor}}$= \(8\)
Special value: $L^{(r)}(E/K,1)/r!$ \( 1.68991921609341 \)
Analytic order of Ш: Ш${}_{\mathrm{an}}$= \( 1 \) (rounded)

BSD formula

$$\begin{aligned}1.689919216 \approx L'(E/K,1) & \overset{?}{=} \frac{ \# ะจ(E/K) \cdot \Omega(E/K) \cdot \mathrm{Reg}_{\mathrm{NT}}(E/K) \cdot \prod_{\mathfrak{p}} c_{\mathfrak{p}} } { \#E(K)_{\mathrm{tor}}^2 \cdot \left|d_K\right|^{1/2} } \\ & \approx \frac{ 1 \cdot 713.531591 \cdot 2.211622 \cdot 8 } { {8^2 \cdot 116.726175} } \\ & \approx 1.689919216 \end{aligned}$$

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 is only one prime $\frak{p}$ of bad reduction.

$\mathfrak{p}$ $N(\mathfrak{p})$ Tamagawa number Kodaira symbol Reduction type Root number \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{N}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{D}_{\mathrm{min}}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathrm{den}(j))\)
\((1/2a^3-3/2a^2-5/2a+6)\) \(4\) \(8\) \(I_{8}\) 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
\(2\) 2B

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 4 and 8.
Its isogeny class 4.2-b 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.