Properties

Label 4.4.13625.1-4.1-b2
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

\({y}^2+\left(\frac{1}{2}a^{2}-\frac{1}{2}a-\frac{5}{2}\right){x}{y}+\left(\frac{1}{2}a^{3}-4a-\frac{5}{2}\right){y}={x}^{3}+\left(-\frac{1}{2}a^{3}+5a+\frac{9}{2}\right){x}^{2}+\left(-\frac{9}{2}a^{3}-\frac{11}{2}a^{2}+\frac{65}{2}a+47\right){x}-\frac{29}{2}a^{3}-\frac{39}{2}a^{2}+\frac{185}{2}a+133\)
Copy content comment:Define the curve
 
Copy content sage:E = EllipticCurve([K([-5/2,-1/2,1/2,0]),K([9/2,5,0,-1/2]),K([-5/2,-4,0,1/2]),K([47,65/2,-11/2,-9/2]),K([133,185/2,-39/2,-29/2])])
 
Copy content gp:E = ellinit([Polrev([-5/2,-1/2,1/2,0]),Polrev([9/2,5,0,-1/2]),Polrev([-5/2,-4,0,1/2]),Polrev([47,65/2,-11/2,-9/2]),Polrev([133,185/2,-39/2,-29/2])], K);
 
Copy content magma:E := EllipticCurve([K![-5/2,-1/2,1/2,0],K![9/2,5,0,-1/2],K![-5/2,-4,0,1/2],K![47,65/2,-11/2,-9/2],K![133,185/2,-39/2,-29/2]]);
 
Copy content oscar:E = elliptic_curve([K([-5/2,-1/2,1/2,0]),K([9/2,5,0,-1/2]),K([-5/2,-4,0,1/2]),K([47,65/2,-11/2,-9/2]),K([133,185/2,-39/2,-29/2])])
 

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

\(\Z \oplus \Z/{2}\Z \oplus \Z/{4}\Z\)

Mordell-Weil generators

$P$$\hat{h}(P)$Order
$\left(\frac{29}{8} a^{3} + \frac{19}{4} a^{2} - \frac{91}{4} a - \frac{255}{8} : -36 a^{3} - \frac{809}{16} a^{2} + \frac{3563}{16} a + \frac{5219}{16} : 1\right)$$1.1058112019939555148501196683306878588$$\infty$
$\left(\frac{1}{8} a^{3} - \frac{1}{4} a^{2} - \frac{7}{4} a - \frac{11}{8} : \frac{5}{16} a^{2} + \frac{1}{16} a - \frac{23}{16} : 1\right)$$0$$2$
$\left(-\frac{1}{2} a^{2} - \frac{1}{2} a + \frac{3}{2} : \frac{1}{2} a^{2} + \frac{1}{2} a - \frac{3}{2} : 1\right)$$0$$4$

Invariants

Conductor: $\frak{N}$ = \((-1/2a^3-a^2+3a+11/2)\) = \((-1/2a^3-a^2+3a+11/2)\)
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: $N(\frak{N})$ = \( 4 \) = \(4\)
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: $\Delta$ = $-1/2a^3+2a^2+4a-27/2$
Discriminant ideal: $\frak{D}_{\mathrm{min}} = (\Delta)$ = \((-1/2a^3+2a^2+4a-27/2)\) = \((-1/2a^3-a^2+3a+11/2)^{4}\)
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: $N(\frak{D}_{\mathrm{min}}) = N(\Delta)$ = \( 256 \) = \(4^{4}\)
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: $j$ = \( \frac{10570617}{32} a^{3} - \frac{9262425}{8} a^{2} - \frac{30217737}{16} a + \frac{218496889}{32} \)
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: $\mathrm{Reg}(E/K)$ \( 1.1058112019939555148501196683306878588 \)
Néron-Tate Regulator: $\mathrm{Reg}_{\mathrm{NT}}(E/K)$ \( 4.4232448079758220594004786733227514352 \)
Global period: $\Omega(E/K)$ \( 713.53159130117649670636356812462591989 \)
Tamagawa product: $\prod_{\frak{p}}c_{\frak{p}}$= \( 4 \)
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

$$\begin{aligned}1.689919216 \approx L'(E/K,1) & \overset{?}{=} \frac{ \# ะจ(E/K) \cdot \Omega(E/K) \cdot \mathrm{Reg}_{\mathrm{NT}}(E/K) \cdot \prod_{\mathfrak{p}} c_{\mathfrak{p}} } { \#E(K)_{\mathrm{tor}}^2 \cdot \left|d_K\right|^{1/2} } \\ & \approx \frac{ 1 \cdot 713.531591 \cdot 4.423245 \cdot 4 } { {8^2 \cdot 116.726175} } \\ & \approx 1.689919216 \end{aligned}$$

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 \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{N}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathfrak{D}_{\mathrm{min}}\)) \(\mathrm{ord}_{\mathfrak{p}}(\mathrm{den}(j))\)
\((-1/2a^3-a^2+3a+11/2)\) \(4\) \(4\) \(I_{4}\) Split multiplicative \(-1\) \(1\) \(4\) \(4\)

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 4.1-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.