Properties

Label 2.0.31.1-10.1-a4
Base field \(\Q(\sqrt{-31}) \)
Conductor norm \( 10 \)
CM no
Base change no
Q-curve no
Torsion order \( 2 \)
Rank \( 0 \)

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Base field \(\Q(\sqrt{-31}) \)

Generator \(a\), with minimal polynomial \( x^{2} - x + 8 \); class number \(3\).

sage: R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([8, -1, 1]))
 
gp: K = nfinit(Polrev([8, -1, 1]));
 
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![8, -1, 1]);
 

Weierstrass equation

\({y}^2+{x}{y}+{y}={x}^3+\left(-a-1\right){x}^2+\left(-4a+17\right){x}+12a-1\)
sage: E = EllipticCurve([K([1,0]),K([-1,-1]),K([1,0]),K([17,-4]),K([-1,12])])
 
gp: E = ellinit([Polrev([1,0]),Polrev([-1,-1]),Polrev([1,0]),Polrev([17,-4]),Polrev([-1,12])], K);
 
magma: E := EllipticCurve([K![1,0],K![-1,-1],K![1,0],K![17,-4],K![-1,12]]);
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

Conductor: \((10,a+6)\) = \((2,a)\cdot(5,a+1)\)
sage: E.conductor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
Conductor norm: \( 10 \) = \(2\cdot5\)
sage: E.conductor().norm()
 
gp: idealnorm(ellglobalred(E)[1])
 
magma: Norm(Conductor(E));
 
Discriminant: \((-96559a+890296)\) = \((2,a)^{7}\cdot(5,a+1)^{14}\)
sage: E.discriminant()
 
gp: E.disc
 
magma: Discriminant(E);
 
Discriminant norm: \( 781250000000 \) = \(2^{7}\cdot5^{14}\)
sage: E.discriminant().norm()
 
gp: norm(E.disc)
 
magma: Norm(Discriminant(E));
 
j-invariant: \( \frac{379001974281391}{781250000000} a - \frac{103373105456887}{781250000000} \)
sage: E.j_invariant()
 
gp: E.j
 
magma: jInvariant(E);
 
Endomorphism ring: \(\Z\)
Geometric endomorphism ring: \(\Z\) (no potential complex multiplication)
sage: E.has_cm(), E.cm_discriminant()
 
magma: HasComplexMultiplication(E);
 
Sato-Tate group: $\mathrm{SU}(2)$

Mordell-Weil group

Rank: \(0\)
Torsion structure: \(\Z/2\Z\)
sage: T = E.torsion_subgroup(); T.invariants()
 
gp: T = elltors(E); T[2]
 
magma: T,piT := TorsionSubgroup(E); Invariants(T);
 
Torsion generator: $\left(\frac{9}{4} a + \frac{3}{4} : -\frac{9}{8} a - \frac{7}{8} : 1\right)$
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: \( 1.3856808303742949919228263459766195470 \)
Tamagawa product: \( 14 \)  =  \(7\cdot2\)
Torsion order: \(2\)
Leading coefficient: \( 1.7421293683646124420071153053250935988 \)
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\((j)_{-}\)
\((2,a)\) \(2\) \(7\) \(I_{7}\) Split multiplicative \(-1\) \(1\) \(7\) \(7\)
\((5,a+1)\) \(5\) \(2\) \(I_{14}\) Non-split multiplicative \(1\) \(1\) \(14\) \(14\)

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
\(7\) 7B.2.3

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 7 and 14.
Its isogeny class 10.1-a consists of curves linked by isogenies of degrees dividing 14.

Base change

This elliptic curve is not a \(\Q\)-curve.

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