Properties

Label 28830h1
Conductor 28830
Discriminant -1917007950960
j-invariant \( \frac{357911}{2160} \)
CM no
Rank 2
Torsion Structure \(\Z/{2}\Z\)

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Minimal Weierstrass equation

sage: E = EllipticCurve([1, 1, 0, 1422, -62748]) # or
 
sage: E = EllipticCurve("28830h1")
 
gp: E = ellinit([1, 1, 0, 1422, -62748]) \\ or
 
gp: E = ellinit("28830h1")
 
magma: E := EllipticCurve([1, 1, 0, 1422, -62748]); // or
 
magma: E := EllipticCurve("28830h1");
 

\( y^2 + x y = x^{3} + x^{2} + 1422 x - 62748 \)

Mordell-Weil group structure

\(\Z^2 \times \Z/{2}\Z\)

Infinite order Mordell-Weil generators and heights

sage: E.gens()
 
magma: Generators(E);
 

\(P\) =  \( \left(59, -510\right) \)\( \left(284, 4690\right) \)
\(\hat{h}(P)\) ≈  1.06113421421842065.0428770361631825

Torsion generators

sage: E.torsion_subgroup().gens()
 
gp: elltors(E)
 
magma: TorsionSubgroup(E);
 

\( \left(28, -14\right) \)

Integral points

sage: E.integral_points()
 
magma: IntegralPoints(E);
 

\( \left(28, -14\right) \), \( \left(37, 187\right) \), \( \left(37, -224\right) \), \( \left(59, 451\right) \), \( \left(59, -510\right) \), \( \left(152, 1846\right) \), \( \left(152, -1998\right) \), \( \left(284, 4690\right) \), \( \left(284, -4974\right) \)

Invariants

sage: E.conductor().factor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
Conductor: \( 28830 \)  =  \(2 \cdot 3 \cdot 5 \cdot 31^{2}\)
sage: E.discriminant().factor()
 
gp: E.disc
 
magma: Discriminant(E);
 
Discriminant: \(-1917007950960 \)  =  \(-1 \cdot 2^{4} \cdot 3^{3} \cdot 5 \cdot 31^{6} \)
sage: E.j_invariant().factor()
 
gp: E.j
 
magma: jInvariant(E);
 
j-invariant: \( \frac{357911}{2160} \)  =  \(2^{-4} \cdot 3^{-3} \cdot 5^{-1} \cdot 71^{3}\)
Endomorphism ring: \(\Z\)   (no Complex Multiplication)
Sato-Tate Group: $\mathrm{SU}(2)$

BSD invariants

sage: E.rank()
 
magma: Rank(E);
 
Rank: \(2\)
sage: E.regulator()
 
magma: Regulator(E);
 
Regulator: \(5.31917068463\)
sage: E.period_lattice().omega()
 
gp: E.omega[1]
 
magma: RealPeriod(E);
 
Real period: \(0.416106730036\)
sage: E.tamagawa_numbers()
 
gp: gr=ellglobalred(E); [[gr[4][i,1],gr[5][i][4]] | i<-[1..#gr[4][,1]]]
 
magma: TamagawaNumbers(E);
 
Tamagawa product: \( 8 \)  = \( 2\cdot1\cdot1\cdot2^{2} \)
sage: E.torsion_order()
 
gp: elltors(E)[1]
 
magma: Order(TorsionSubgroup(E));
 
Torsion order: \(2\)
sage: E.sha().an_numerical()
 
magma: MordellWeilShaInformation(E);
 
Analytic order of Ш: \(1\) (rounded)

Modular invariants

Modular form 28830.2.a.a

sage: E.q_eigenform(20)
 
gp: xy = elltaniyama(E);
 
gp: x*deriv(xy[1])/(2*xy[2]+E.a1*xy[1]+E.a3)
 
magma: ModularForm(E);
 

\( q - q^{2} - q^{3} + q^{4} - q^{5} + q^{6} - 4q^{7} - q^{8} + q^{9} + q^{10} - q^{12} - 2q^{13} + 4q^{14} + q^{15} + q^{16} - 6q^{17} - q^{18} - 4q^{19} + O(q^{20}) \)

For more coefficients, see the Downloads section to the right.

sage: E.modular_degree()
 
magma: ModularDegree(E);
 
Modular degree: 57600
\( \Gamma_0(N) \)-optimal: yes
Manin constant: 1

Special L-value

sage: r = E.rank();
 
sage: E.lseries().dokchitser().derivative(1,r)/r.factorial()
 
gp: ar = ellanalyticrank(E);
 
gp: ar[2]/factorial(ar[1])
 
magma: Lr1 where r,Lr1 := AnalyticRank(E: Precision:=12);
 

\( L^{(2)}(E,1)/2! \) ≈ \( 4.42668544017 \)

Local data

This elliptic curve is not semistable.

sage: E.local_data()
 
gp: ellglobalred(E)[5]
 
magma: [LocalInformation(E,p) : p in BadPrimes(E)];
 
prime Tamagawa number Kodaira symbol Reduction type Root number ord(\(N\)) ord(\(\Delta\)) ord\((j)_{-}\)
\(2\) \(2\) \( I_{4} \) Non-split multiplicative 1 1 4 4
\(3\) \(1\) \( I_{3} \) Non-split multiplicative 1 1 3 3
\(5\) \(1\) \( I_{1} \) Non-split multiplicative 1 1 1 1
\(31\) \(4\) \( I_0^{*} \) Additive -1 2 6 0

Galois representations

The image of the 2-adic representation attached to this elliptic curve is the subgroup of $\GL(2,\Z_2)$ with Rouse label X13.

This subgroup is the pull-back of the subgroup of $\GL(2,\Z_2/2^2\Z_2)$ generated by $\left(\begin{array}{rr} 3 & 0 \\ 0 & 1 \end{array}\right),\left(\begin{array}{rr} 1 & 1 \\ 0 & 1 \end{array}\right),\left(\begin{array}{rr} 3 & 0 \\ 0 & 3 \end{array}\right)$ and has index 6.

sage: rho = E.galois_representation();
 
sage: [rho.image_type(p) for p in rho.non_surjective()]
 
magma: [GaloisRepresentation(E,p): p in PrimesUpTo(20)];
 

The mod \( p \) Galois representation has maximal image \(\GL(2,\F_p)\) for all primes \( p \) except those listed.

prime Image of Galois representation
\(2\) B
\(3\) B

$p$-adic data

$p$-adic regulators

sage: [E.padic_regulator(p) for p in primes(3,20) if E.conductor().valuation(p)<2]
 

Note: \(p\)-adic regulator data only exists for primes \(p\ge5\) of good ordinary reduction.

Iwasawa invariants

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47
Reduction type nonsplit nonsplit nonsplit ordinary ss ordinary ordinary ordinary ss ordinary add ordinary ordinary ordinary ss
$\lambda$-invariant(s) 16 2 2 6 2,2 2 2 2 2,2 2 - 2 2 2 2,2
$\mu$-invariant(s) 0 0 0 0 0,0 0 0 0 0,0 0 - 0 0 0 0,0

An entry - indicates that the invariants are not computed because the reduction is additive.

Isogenies

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 3, 4, 6 and 12.
Its isogeny class 28830h consists of 8 curves linked by isogenies of degrees dividing 12.

Growth of torsion in number fields

The number fields $K$ of degree up to 7 such that $E(K)_{\rm tors}$ is strictly larger than $E(\Q)_{\rm tors}$ $\cong \Z/{2}\Z$ are as follows:

$[K:\Q]$ $K$ $E(K)_{\rm tors}$ Base-change curve
2 \(\Q(\sqrt{-15}) \) \(\Z/2\Z \times \Z/2\Z\) Not in database
\(\Q(\sqrt{-31}) \) \(\Z/6\Z\) Not in database
\(\Q(\sqrt{93}) \) \(\Z/4\Z\) Not in database
\(\Q(\sqrt{-155}) \) \(\Z/4\Z\) Not in database
4 \(\Q(\sqrt{-3}, \sqrt{-31})\) \(\Z/12\Z\) Not in database
\(\Q(\sqrt{5}, \sqrt{-31})\) \(\Z/12\Z\) Not in database
\(\Q(\sqrt{-15}, \sqrt{-31})\) \(\Z/2\Z \times \Z/6\Z\) Not in database
\(\Q(\sqrt{-15}, \sqrt{93})\) \(\Z/2\Z \times \Z/4\Z\) Not in database
6 6.2.8043570000.4 \(\Z/12\Z\) Not in database

We only show fields where the torsion growth is primitive. For each field $K$ we either show its label, or a defining polynomial when $K$ is not in the database.