Properties

Label 2.0.11.1-121.1-CMa1
Base field \(\Q(\sqrt{-11}) \)
Conductor norm \( 121 \)
CM yes (\(-11\))
Base change yes
Q-curve yes
Torsion order \( 1 \)
Rank \( 2 \)

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Base field \(\Q(\sqrt{-11}) \)

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

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

Weierstrass equation

\({y}^2+{y}={x}^{3}-{x}^{2}-7{x}+10\)
sage: E = EllipticCurve([K([0,0]),K([-1,0]),K([1,0]),K([-7,0]),K([10,0])])
 
gp: E = ellinit([Polrev([0,0]),Polrev([-1,0]),Polrev([1,0]),Polrev([-7,0]),Polrev([10,0])], K);
 
magma: E := EllipticCurve([K![0,0],K![-1,0],K![1,0],K![-7,0],K![10,0]]);
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

Conductor: \((11)\) = \((-2a+1)^{2}\)
sage: E.conductor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
Conductor norm: \( 121 \) = \(11^{2}\)
sage: E.conductor().norm()
 
gp: idealnorm(ellglobalred(E)[1])
 
magma: Norm(Conductor(E));
 
Discriminant: \((-1331)\) = \((-2a+1)^{6}\)
sage: E.discriminant()
 
gp: E.disc
 
magma: Discriminant(E);
 
Discriminant norm: \( 1771561 \) = \(11^{6}\)
sage: E.discriminant().norm()
 
gp: norm(E.disc)
 
magma: Norm(Discriminant(E));
 
j-invariant: \( -32768 \)
sage: E.j_invariant()
 
gp: E.j
 
magma: jInvariant(E);
 
Endomorphism ring: \(\Z[(1+\sqrt{-11})/2]\) (complex multiplication)
Geometric endomorphism ring: \(\Z[(1+\sqrt{-11})/2]\)
sage: E.has_cm(), E.cm_discriminant()
 
magma: HasComplexMultiplication(E);
 
Sato-Tate group: $\mathrm{U}(1)$

Mordell-Weil group

Rank: \(2\)
Generators $\left(-\frac{2}{9} a + \frac{5}{3} : -\frac{11}{27} a - \frac{10}{9} : 1\right)$ $\left(4 : 5 : 1\right)$
Heights \(0.44892578080345226663151545082504359911\) \(0.089785156160690453326303090165008719822\)
Torsion structure: trivial
sage: T = E.torsion_subgroup(); T.invariants()
 
gp: T = elltors(E); T[2]
 
magma: T,piT := TorsionSubgroup(E); Invariants(T);
 

BSD invariants

Analytic rank: \( 2 \)
sage: E.rank()
 
magma: Rank(E);
 
Mordell-Weil rank: \(2\)
Regulator: \( 0.022168779233698819878879540118695732679 \)
Period: \( 3.4769158424352161557941951589028318460 \)
Tamagawa product: \( 4 \)
Torsion order: \(1\)
Leading coefficient: \( 0.74368597809907052242861130738004104123 \)
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\((j)_{-}\)
\((-2a+1)\) \(11\) \(4\) \(I_0^{*}\) Additive \(-1\) \(2\) \(6\) \(0\)

Galois Representations

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

prime Image of Galois Representation
\(11\) 11B.1.5[2]

For all other primes \(p\), the image is a split Cartan subgroup if \(\left(\frac{ -11 }{p}\right)=+1\) or a nonsplit Cartan subgroup if \(\left(\frac{ -11 }{p}\right)=-1\).

Isogenies and isogeny class

This curve has no rational isogenies other than endomorphisms. Its isogeny class 121.1-CMa consists of this curve only.

Base change

This elliptic curve is a \(\Q\)-curve. It is the base change of the following 2 elliptic curves:

Base field Curve
\(\Q\) 121.b1
\(\Q\) 121.b2