Properties

 Label 15246bs1 Conductor $15246$ Discriminant $-2.083\times 10^{13}$ j-invariant $$-\frac{7189057}{16128}$$ CM no Rank $1$ Torsion structure $$\Z/{2}\Z$$

Related objects

Show commands for: Magma / Pari/GP / SageMath

Minimal Weierstrass equation

sage: E = EllipticCurve([1, -1, 1, -4379, 247371]) # or

sage: E = EllipticCurve("15246.bo5")

gp: E = ellinit([1, -1, 1, -4379, 247371]) \\ or

gp: E = ellinit("15246.bo5")

magma: E := EllipticCurve([1, -1, 1, -4379, 247371]); // or

magma: E := EllipticCurve("15246.bo5");

$$y^2+xy+y=x^3-x^2-4379x+247371$$

Mordell-Weil group structure

$$\Z\times \Z/{2}\Z$$

Infinite order Mordell-Weil generator and height

sage: E.gens()

magma: Generators(E);

 $$P$$ = $$\left(3, 482\right)$$ $$\hat{h}(P)$$ ≈ $0.87344300190114259721215492099$

Torsion generators

sage: E.torsion_subgroup().gens()

gp: elltors(E)

magma: TorsionSubgroup(E);

$$\left(-85, 42\right)$$

Integral points

sage: E.integral_points()

magma: IntegralPoints(E);

$$\left(-85, 42\right)$$, $$\left(3, 482\right)$$, $$\left(3, -486\right)$$, $$\left(15, 422\right)$$, $$\left(15, -438\right)$$, $$\left(113, 1032\right)$$, $$\left(113, -1146\right)$$

Invariants

 sage: E.conductor().factor()  gp: ellglobalred(E)[1]  magma: Conductor(E); Conductor: $$15246$$ = $$2 \cdot 3^{2} \cdot 7 \cdot 11^{2}$$ sage: E.discriminant().factor()  gp: E.disc  magma: Discriminant(E); Discriminant: $$-20828795404032$$ = $$-1 \cdot 2^{8} \cdot 3^{8} \cdot 7 \cdot 11^{6}$$ sage: E.j_invariant().factor()  gp: E.j  magma: jInvariant(E); j-invariant: $$-\frac{7189057}{16128}$$ = $$-1 \cdot 2^{-8} \cdot 3^{-2} \cdot 7^{-1} \cdot 193^{3}$$ Endomorphism ring: $$\Z$$ Geometric endomorphism ring: $$\Z$$ (no potential complex multiplication) Sato-Tate group: $\mathrm{SU}(2)$

BSD invariants

 sage: E.rank()  magma: Rank(E); Analytic rank: $$1$$ sage: E.regulator()  magma: Regulator(E); Regulator: $$0.87344300190114259721215492099$$ sage: E.period_lattice().omega()  gp: E.omega[1]  magma: RealPeriod(E); Real period: $$0.60499774679823613239689127738$$ 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: $$64$$  = $$2^{3}\cdot2\cdot1\cdot2^{2}$$ 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: $$1$$ (exact)

Modular invariants

Modular form 15246.2.a.bo

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);

$$q + q^{2} + q^{4} + 2q^{5} + q^{7} + q^{8} + 2q^{10} - 6q^{13} + q^{14} + q^{16} + 2q^{17} + 4q^{19} + O(q^{20})$$

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

 sage: E.modular_degree()  magma: ModularDegree(E); Modular degree: 40960 $$\Gamma_0(N)$$-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);

$$L'(E,1)$$ ≈ $$8.4548967697100599975142117267614809791$$

Local data

This elliptic curve is semistable. There are 4 primes of bad reduction:

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$$(j)_{-}$$
$$2$$ $$8$$ $$I_{8}$$ Split multiplicative -1 1 8 8
$$3$$ $$2$$ $$I_2^{*}$$ Additive -1 2 8 2
$$7$$ $$1$$ $$I_{1}$$ Split multiplicative -1 1 1 1
$$11$$ $$4$$ $$I_0^{*}$$ 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 X230.

This subgroup is the pull-back of the subgroup of $\GL(2,\Z_2/2^4\Z_2)$ generated by $\left(\begin{array}{rr} 7 & 7 \\ 0 & 7 \end{array}\right),\left(\begin{array}{rr} 3 & 0 \\ 8 & 1 \end{array}\right),\left(\begin{array}{rr} 7 & 0 \\ 0 & 7 \end{array}\right),\left(\begin{array}{rr} 1 & 0 \\ 0 & 7 \end{array}\right)$ and has index 48.

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

$p$-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 $$p\ge 5$$ of good ordinary reduction.

Iwasawa invariants

 $p$ Reduction type $\lambda$-invariant(s) $\mu$-invariant(s) 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 split add ordinary split add ordinary ordinary ordinary ordinary ordinary ss ordinary ordinary ordinary ss 4 - 1 2 - 1 1 1 1 1 1,1 1 1 1 1,1 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, 4 and 8.
Its isogeny class 15246bs consists of 6 curves linked by isogenies of degrees dividing 8.

Growth of torsion in number fields

The number fields $K$ of degree less than 24 such that $E(K)_{\rm tors}$ is strictly larger than $E(\Q)_{\rm tors}$ $\cong \Z/{2}\Z$ are as follows:

 $[K:\Q]$ $E(K)_{\rm tors}$ Base change curve $K$ $2$ $$\Q(\sqrt{-7})$$ $$\Z/2\Z \times \Z/2\Z$$ Not in database $2$ $$\Q(\sqrt{33})$$ $$\Z/8\Z$$ 2.2.33.1-588.1-e1 $2$ $$\Q(\sqrt{-231})$$ $$\Z/4\Z$$ Not in database $4$ $$\Q(\sqrt{-7}, \sqrt{33})$$ $$\Z/2\Z \times \Z/8\Z$$ Not in database $8$ 8.0.35717739450624.29 $$\Z/2\Z \times \Z/4\Z$$ Not in database $8$ 8.0.35717739450624.25 $$\Z/8\Z$$ Not in database $8$ 8.4.238019088384.12 $$\Z/16\Z$$ Not in database $8$ Deg 8 $$\Z/6\Z$$ Not in database $16$ Deg 16 $$\Z/4\Z \times \Z/8\Z$$ Not in database $16$ Deg 16 $$\Z/2\Z \times \Z/16\Z$$ Not in database $16$ Deg 16 $$\Z/2\Z \times \Z/16\Z$$ Not in database $16$ Deg 16 $$\Z/16\Z$$ Not in database $16$ Deg 16 $$\Z/2\Z \times \Z/6\Z$$ Not in database $16$ Deg 16 $$\Z/24\Z$$ Not in database $16$ Deg 16 $$\Z/12\Z$$ Not in database

We only show fields where the torsion growth is primitive. For fields not in the database, click on the degree shown to reveal the defining polynomial.