Properties

Base field \(\Q(\sqrt{3}) \)
Label 2.2.12.1-392.1-d1
Conductor \((14 a + 14)\)
Conductor norm \( 392 \)
CM no
base-change yes: 56.a4,1008.d4
Q-curve yes
Torsion order \( 4 \)
Rank not available

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

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

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![-3, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^2 - 3)
 
gp (2.8): K = nfinit(a^2 - 3);
 

Weierstrass equation

\( y^2 + \left(a + 1\right) x y + \left(a + 1\right) y = x^{3} + \left(a - 1\right) x^{2} + \left(-2 a + 2\right) x - 3 a + 4 \)
magma: E := ChangeRing(EllipticCurve([a + 1, a - 1, a + 1, -2*a + 2, -3*a + 4]),K);
 
sage: E = EllipticCurve(K, [a + 1, a - 1, a + 1, -2*a + 2, -3*a + 4])
 
gp (2.8): E = ellinit([a + 1, a - 1, a + 1, -2*a + 2, -3*a + 4],K)
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

\(\mathfrak{N} \) = \((14 a + 14)\) = \( \left(a + 1\right)^{3} \cdot \left(7\right) \)
magma: Conductor(E);
 
sage: E.conductor()
 
\(N(\mathfrak{N}) \) = \( 392 \) = \( 2^{3} \cdot 49 \)
magma: Norm(Conductor(E));
 
sage: E.conductor().norm()
 
\(\mathfrak{D}\) = \((28)\) = \( \left(a + 1\right)^{4} \cdot \left(7\right) \)
magma: Discriminant(E);
 
sage: E.discriminant()
 
gp (2.8): E.disc
 
\(N(\mathfrak{D})\) = \( 784 \) = \( 2^{4} \cdot 49 \)
magma: Norm(Discriminant(E));
 
sage: E.discriminant().norm()
 
gp (2.8): norm(E.disc)
 
\(j\) = \( \frac{432}{7} \)
magma: jInvariant(E);
 
sage: E.j_invariant()
 
gp (2.8): E.j
 
\( \text{End} (E) \) = \(\Z\)   (no Complex Multiplication )
magma: HasComplexMultiplication(E);
 
sage: E.has_cm(), E.cm_discriminant()
 
\( \text{ST} (E) \) = $\mathrm{SU}(2)$

Mordell-Weil group

Rank not available.
magma: Rank(E);
 
sage: E.rank()
 
magma: Generators(E); // includes torsion
 
sage: E.gens()
 

Regulator: not available

magma: Regulator(Generators(E));
 
sage: E.regulator_of_points(E.gens())
 

Torsion subgroup

Structure: \(\Z/4\Z\)
magma: TorsionSubgroup(E);
 
sage: E.torsion_subgroup().gens()
 
gp (2.8): elltors(E)[2]
 
magma: Order(TorsionSubgroup(E));
 
sage: E.torsion_order()
 
gp (2.8): elltors(E)[1]
 
Generator: $\left(-a + 1 : -2 a + 3 : 1\right)$
magma: [f(P): P in Generators(T)] where T,f:=TorsionSubgroup(E);
 
sage: E.torsion_subgroup().gens()
 
gp (2.8): elltors(E)[3]
 

Local data at primes of bad reduction

magma: LocalInformation(E);
 
sage: E.local_data()
 
prime Norm Tamagawa number Kodaira symbol Reduction type Root number ord(\(\mathfrak{N}\)) ord(\(\mathfrak{D}\)) ord\((j)_{-}\)
\( \left(a + 1\right) \) \(2\) \(2\) \(III\) Additive \(1\) \(3\) \(4\) \(0\)
\( \left(7\right) \) \(49\) \(1\) \(I_{1}\) Split multiplicative \(-1\) \(1\) \(1\) \(1\)

Galois Representations

The mod \( p \) Galois Representation has maximal image for all primes \( p \) 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 and 4.
Its isogeny class 392.1-d consists of curves linked by isogenies of degrees dividing 4.

Base change

This curve is the base-change of elliptic curves 56.a4, 1008.d4, defined over \(\Q\), so it is also a \(\Q\)-curve.