Properties

Base field 5.5.24217.1
Label 5.5.24217.1-85.2-b2
Conductor \((85,a^{4} - 5 a^{2} - 2 a + 3)\)
Conductor norm \( 85 \)
CM no
base-change no
Q-curve no
Torsion order \( 2 \)
Rank not available

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Base field 5.5.24217.1

Generator \(a\), with minimal polynomial \( x^{5} - 5 x^{3} - x^{2} + 3 x + 1 \); class number \(1\).

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, 3, -1, -5, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^5 - 5*x^3 - x^2 + 3*x + 1)
 
gp (2.8): K = nfinit(a^5 - 5*a^3 - a^2 + 3*a + 1);
 

Weierstrass equation

\( y^2 + \left(a^{4} - a^{3} - 4 a^{2} + 4 a + 2\right) x y + \left(a^{4} - a^{3} - 4 a^{2} + 4 a + 2\right) y = x^{3} + \left(-3 a^{4} + a^{3} + 14 a^{2} - 3 a - 6\right) x^{2} + \left(-50 a^{4} + 26 a^{3} + 232 a^{2} - 74 a - 103\right) x + 65 a^{4} - 10 a^{3} - 330 a^{2} - 4 a + 225 \)
magma: E := ChangeRing(EllipticCurve([a^4 - a^3 - 4*a^2 + 4*a + 2, -3*a^4 + a^3 + 14*a^2 - 3*a - 6, a^4 - a^3 - 4*a^2 + 4*a + 2, -50*a^4 + 26*a^3 + 232*a^2 - 74*a - 103, 65*a^4 - 10*a^3 - 330*a^2 - 4*a + 225]),K);
 
sage: E = EllipticCurve(K, [a^4 - a^3 - 4*a^2 + 4*a + 2, -3*a^4 + a^3 + 14*a^2 - 3*a - 6, a^4 - a^3 - 4*a^2 + 4*a + 2, -50*a^4 + 26*a^3 + 232*a^2 - 74*a - 103, 65*a^4 - 10*a^3 - 330*a^2 - 4*a + 225])
 
gp (2.8): E = ellinit([a^4 - a^3 - 4*a^2 + 4*a + 2, -3*a^4 + a^3 + 14*a^2 - 3*a - 6, a^4 - a^3 - 4*a^2 + 4*a + 2, -50*a^4 + 26*a^3 + 232*a^2 - 74*a - 103, 65*a^4 - 10*a^3 - 330*a^2 - 4*a + 225],K)
 

This is a global minimal model.

sage: E.is_global_minimal_model()
 

Invariants

\(\mathfrak{N} \) = \((85,a^{4} - 5 a^{2} - 2 a + 3)\) = \( \left(2 a^{4} - a^{3} - 9 a^{2} + 2 a + 3\right) \cdot \left(a^{2} - a - 3\right) \)
magma: Conductor(E);
 
sage: E.conductor()
 
\(N(\mathfrak{N}) \) = \( 85 \) = \( 5 \cdot 17 \)
magma: Norm(Conductor(E));
 
sage: E.conductor().norm()
 
\(\mathfrak{D}\) = \((1445,a^{4} - 5 a^{2} + 79,-a^{4} + 5 a^{2} + a + 554,2 a^{4} - a^{3} - 9 a^{2} + 3 a + 566,-a^{4} + a^{3} + 5 a^{2} - 3 a + 534)\) = \( \left(2 a^{4} - a^{3} - 9 a^{2} + 2 a + 3\right) \cdot \left(a^{2} - a - 3\right)^{2} \)
magma: Discriminant(E);
 
sage: E.discriminant()
 
gp (2.8): E.disc
 
\(N(\mathfrak{D})\) = \( 1445 \) = \( 5 \cdot 17^{2} \)
magma: Norm(Discriminant(E));
 
sage: E.discriminant().norm()
 
gp (2.8): norm(E.disc)
 
\(j\) = \( \frac{185066934807448}{1445} a^{4} - \frac{87464764407119}{1445} a^{3} - \frac{909727616081443}{1445} a^{2} + \frac{231799410298786}{1445} a + \frac{559295724774971}{1445} \)
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: \(\Z/2\Z\)
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: $\left(\frac{15}{4} a^{4} - \frac{3}{2} a^{3} - \frac{71}{4} a^{2} + \frac{15}{4} a + \frac{35}{4} : \frac{1}{4} a^{4} - \frac{3}{8} a^{3} - \frac{13}{8} a^{2} + \frac{1}{2} a + \frac{1}{4} : 1\right)$
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\((j)_{-}\)
\( \left(2 a^{4} - a^{3} - 9 a^{2} + 2 a + 3\right) \) \(5\) \(1\) \(I_{1}\) Non-split multiplicative \(1\) \(1\) \(1\) \(1\)
\( \left(a^{2} - a - 3\right) \) \(17\) \(2\) \(I_{2}\) Non-split multiplicative \(1\) \(1\) \(2\) \(2\)

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.
Its isogeny class 85.2-b consists of curves linked by isogenies of degree 2.

Base change

This curve is not the base-change of an elliptic curve defined over \(\Q\). It is not a \(\Q\)-curve.