Properties

Label 4.4.1125.1-45.1-a1
Base field \(\Q(\zeta_{15})^+\)
Conductor \((a^3-5a+1)\)
Conductor norm \( 45 \)
CM no
Base change yes: 45.a8,225.b8
Q-curve yes
Torsion order \( 2 \)
Rank \( 0 \)

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Base field \(\Q(\zeta_{15})^+\)

Generator \(a\), with minimal polynomial \( x^{4} - x^{3} - 4 x^{2} + 4 x + 1 \); class number \(1\).

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

Weierstrass equation

\({y}^2+\left(a^{3}+a^{2}-2a-2\right){x}{y}+\left(a^{3}+a^{2}-2a-1\right){y}={x}^{3}+\left(-a^{3}+a^{2}+4a-3\right){x}^{2}+\left(-35a^{3}+174a^{2}-140a-32\right){x}-328a^{3}+1241a^{2}-884a-245\)
sage: E = EllipticCurve([K([-2,-2,1,1]),K([-3,4,1,-1]),K([-1,-2,1,1]),K([-32,-140,174,-35]),K([-245,-884,1241,-328])])
 
gp: E = ellinit([Pol(Vecrev([-2,-2,1,1])),Pol(Vecrev([-3,4,1,-1])),Pol(Vecrev([-1,-2,1,1])),Pol(Vecrev([-32,-140,174,-35])),Pol(Vecrev([-245,-884,1241,-328]))], K);
 
magma: E := EllipticCurve([K![-2,-2,1,1],K![-3,4,1,-1],K![-1,-2,1,1],K![-32,-140,174,-35],K![-245,-884,1241,-328]]);
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

Conductor: \((a^3-5a+1)\) = \((-a-1)\cdot(-a^3+a^2+3a-2)\)
sage: E.conductor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
Conductor norm: \( 45 \) = \(5\cdot9\)
sage: E.conductor().norm()
 
gp: idealnorm(ellglobalred(E)[1])
 
magma: Norm(Conductor(E));
 
Discriminant: \((-3515625)\) = \((-a-1)^{32}\cdot(-a^3+a^2+3a-2)^{4}\)
sage: E.discriminant()
 
gp: E.disc
 
magma: Discriminant(E);
 
Discriminant norm: \( 152760185301303863525390625 \) = \(5^{32}\cdot9^{4}\)
sage: E.discriminant().norm()
 
gp: norm(E.disc)
 
magma: Norm(Discriminant(E));
 
j-invariant: \( \frac{4733169839}{3515625} \)
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: $\left(-\frac{7}{4} a^{2} + \frac{3}{4} a + 1 : \frac{7}{4} a^{3} - \frac{29}{8} a + \frac{1}{8} : 1\right)$
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: \( 6.49224912494178 \)
Tamagawa product: \( 4 \)  =  \(2\cdot2\)
Torsion order: \(2\)
Leading coefficient: \( 0.774245886412445 \)
Analytic order of Ш: \( 4 \) (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\((j)_{-}\)
\((-a-1)\) \(5\) \(2\) \(I_{32}\) Non-split multiplicative \(1\) \(1\) \(32\) \(32\)
\((-a^3+a^2+3a-2)\) \(9\) \(2\) \(I_{4}\) Non-split multiplicative \(1\) \(1\) \(4\) \(4\)

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

Isogenies and isogeny class

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 4, 8 and 16.
Its isogeny class 45.1-a consists of curves linked by isogenies of degrees dividing 32.

Base change

This curve is the base change of 45.a8, 225.b8, defined over \(\Q\), so it is also a \(\Q\)-curve.