Properties

Label 4.4.2304.1-16.1-b1
Base field \(\Q(\sqrt{2}, \sqrt{3})\)
Conductor norm \( 16 \)
CM yes (\(-192\))
Base change no
Q-curve yes
Torsion order \( 4 \)
Rank \( 0 \)

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Base field \(\Q(\sqrt{2}, \sqrt{3})\)

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

sage: R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([1, 0, -4, 0, 1]))
 
gp: K = nfinit(Polrev([1, 0, -4, 0, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 0, -4, 0, 1]);
 

Weierstrass equation

\({y}^2+\left(a^{3}+a^{2}-4a-2\right){x}{y}+\left(a^{3}-4a+1\right){y}={x}^{3}+\left(a^{2}-1\right){x}^{2}+\left(-49a^{3}-26a^{2}+177a+85\right){x}-168a^{3}-86a^{2}+634a+334\)
sage: E = EllipticCurve([K([-2,-4,1,1]),K([-1,0,1,0]),K([1,-4,0,1]),K([85,177,-26,-49]),K([334,634,-86,-168])])
 
gp: E = ellinit([Polrev([-2,-4,1,1]),Polrev([-1,0,1,0]),Polrev([1,-4,0,1]),Polrev([85,177,-26,-49]),Polrev([334,634,-86,-168])], K);
 
magma: E := EllipticCurve([K![-2,-4,1,1],K![-1,0,1,0],K![1,-4,0,1],K![85,177,-26,-49],K![334,634,-86,-168]]);
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

Conductor: \((2)\) = \((a^3-4a+1)^{4}\)
sage: E.conductor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
Conductor norm: \( 16 \) = \(2^{4}\)
sage: E.conductor().norm()
 
gp: idealnorm(ellglobalred(E)[1])
 
magma: Norm(Conductor(E));
 
Discriminant: \((4)\) = \((a^3-4a+1)^{8}\)
sage: E.discriminant()
 
gp: E.disc
 
magma: Discriminant(E);
 
Discriminant norm: \( 256 \) = \(2^{8}\)
sage: E.discriminant().norm()
 
gp: norm(E.disc)
 
magma: Norm(Discriminant(E));
 
j-invariant: \( -600840130180059000 a^{3} + 1160733998424384000 a^{2} + 160994627660022750 a - 311017737504159000 \)
sage: E.j_invariant()
 
gp: E.j
 
magma: jInvariant(E);
 
Endomorphism ring: \(\Z\)
Geometric endomorphism ring: \(\Z[\sqrt{-48}]\) (potential complex multiplication)
sage: E.has_cm(), E.cm_discriminant()
 
magma: HasComplexMultiplication(E);
 
Sato-Tate group: $N(\mathrm{U}(1))$

Mordell-Weil group

Rank: \(0\)
Torsion structure: \(\Z/4\Z\)
sage: T = E.torsion_subgroup(); T.invariants()
 
gp: T = elltors(E); T[2]
 
magma: T,piT := TorsionSubgroup(E); Invariants(T);
 
Torsion generator: $\left(-2 a^{3} - \frac{3}{2} a^{2} + 8 a + \frac{13}{2} : 11 a^{3} + \frac{11}{2} a^{2} - \frac{83}{2} a - 22 : 1\right)$
sage: T.gens()
 
gp: T[3]
 
magma: [piT(P) : P in Generators(T)];
 

BSD invariants

Analytic rank: \( 0 \)
sage: E.rank()
 
magma: Rank(E);
 
Mordell-Weil rank: \(0\)
Regulator: \( 1 \)
Period: \( 626.22830848243234402537533419755294128 \)
Tamagawa product: \( 1 \)
Torsion order: \(4\)
Leading coefficient: \( 0.815401443336501 \)
Analytic order of Ш: \( 1 \) (rounded)

Local data at primes of bad reduction

sage: E.local_data()
 
magma: LocalInformation(E);
 
prime Norm Tamagawa number Kodaira symbol Reduction type Root number ord(\(\mathfrak{N}\)) ord(\(\mathfrak{D}\)) ord\((j)_{-}\)
\((a^3-4a+1)\) \(2\) \(1\) \(I_0^{*}\) Additive \(1\) \(4\) \(8\) \(0\)

Galois Representations

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

The image is a Borel subgroup if \(p\in \{ 2, 3\}\), the normalizer of a split Cartan subgroup if \(\left(\frac{ -3 }{p}\right)=+1\) or the normalizer of a nonsplit Cartan subgroup if \(\left(\frac{ -3 }{p}\right)=-1\).

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 3, 4, 6, 8, 12, 16, 24 and 48.
Its isogeny class 16.1-b consists of curves linked by isogenies of degrees dividing 48.

Base change

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

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