Base field 4.4.13968.1
Generator \(a\), with minimal polynomial \( x^{4} - 2 x^{3} - 7 x^{2} + 8 x + 4 \); class number \(1\).
sage: R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([4, 8, -7, -2, 1]))
gp: K = nfinit(Polrev([4, 8, -7, -2, 1]));
magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![4, 8, -7, -2, 1]);
Weierstrass equation
sage: E = EllipticCurve([K([1,-3,-1/2,1/2]),K([2,-4,-1/2,1/2]),K([-1,1/2,1/2,0]),K([-727,799/2,160,-131/2]),K([7142,-4104,-3261/2,1353/2])])
gp: E = ellinit([Polrev([1,-3,-1/2,1/2]),Polrev([2,-4,-1/2,1/2]),Polrev([-1,1/2,1/2,0]),Polrev([-727,799/2,160,-131/2]),Polrev([7142,-4104,-3261/2,1353/2])], K);
magma: E := EllipticCurve([K![1,-3,-1/2,1/2],K![2,-4,-1/2,1/2],K![-1,1/2,1/2,0],K![-727,799/2,160,-131/2],K![7142,-4104,-3261/2,1353/2]]);
This is a global minimal model.
sage: E.is_global_minimal_model()
Invariants
| Conductor: | \((-1/2a^2+1/2a+3)\) | = | \((1/2a^2+1/2a-1)\cdot(-1/2a^3+1/2a^2+4a-1)\) |
sage: E.conductor()
gp: ellglobalred(E)[1]
magma: Conductor(E);
| |||
| Conductor norm: | \( 4 \) | = | \(2\cdot2\) |
sage: E.conductor().norm()
gp: idealnorm(ellglobalred(E)[1])
magma: Norm(Conductor(E));
| |||
| Discriminant: | \((-24a^3+232a+144)\) | = | \((1/2a^2+1/2a-1)^{9}\cdot(-1/2a^3+1/2a^2+4a-1)^{18}\) |
sage: E.discriminant()
gp: E.disc
magma: Discriminant(E);
| |||
| Discriminant norm: | \( -134217728 \) | = | \(-2^{9}\cdot2^{18}\) |
sage: E.discriminant().norm()
gp: norm(E.disc)
magma: Norm(Discriminant(E));
| |||
| j-invariant: | \( \frac{1533755475209}{1024} a^{3} - \frac{3655919604805}{1024} a^{2} - \frac{2329414733635}{256} a + \frac{3964730446695}{256} \) | ||
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: | \(\Z/18\Z\) |
| sage: T = E.torsion_subgroup(); T.invariants()
gp: T = elltors(E); T[2]
magma: T,piT := TorsionSubgroup(E); Invariants(T);
| |
| Torsion generator: | $\left(a^{3} - 3 a^{2} - 5 a + 14 : -2 a^{3} + 4 a^{2} + 10 a - 12 : 1\right)$ |
| 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: | \( 839.72983296043281064459306155141147920 \) | ||
| Tamagawa product: | \( 162 \) = \(3^{2}\cdot( 2 \cdot 3^{2} )\) | ||
| Torsion order: | \(18\) | ||
| Leading coefficient: | \( 3.55256860685279 \) | ||
| 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\((j)_{-}\) |
|---|---|---|---|---|---|---|---|---|
| \((1/2a^2+1/2a-1)\) | \(2\) | \(9\) | \(I_{9}\) | Split multiplicative | \(-1\) | \(1\) | \(9\) | \(9\) |
| \((-1/2a^3+1/2a^2+4a-1)\) | \(2\) | \(18\) | \(I_{18}\) | Split multiplicative | \(-1\) | \(1\) | \(18\) | \(18\) |
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 |
| \(3\) | 3B.1.1 |
Isogenies and isogeny class
This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\)
2, 3, 6, 9 and 18.
Its isogeny class
4.2-f
consists of curves linked by isogenies of
degrees dividing 18.
Base change
This elliptic curve is not a \(\Q\)-curve.
It is not the base change of an elliptic curve defined over any subfield.