LMFDB - Elliptic curve with Cremona label 31814a1 (LMFDB label 31814.a1)

Show commands: Magma / Oscar / PariGP / SageMath

Simplified equation

$y^2+xy+y=x^3+2x+12$ y^2+xy+y=x^3+2x+12	(homogenize, simplify)
$y^2z+xyz+yz^2=x^3+2xz^2+12z^3$ y^2z+xyz+yz^2=x^3+2xz^2+12z^3	(dehomogenize, simplify)
$y^2=x^3+3213x+561870$ y^2=x^3+3213x+561870	(homogenize, minimize)

comment: Define the curve

sage: E = EllipticCurve([1, 0, 1, 2, 12])

gp: E = ellinit([1, 0, 1, 2, 12])

magma: E := EllipticCurve([1, 0, 1, 2, 12]);

oscar: E = elliptic_curve([1, 0, 1, 2, 12])

sage: E.short_weierstrass_model()

magma: WeierstrassModel(E);

oscar: short_weierstrass_model(E)

Mordell-Weil group structure

$\Z \oplus \Z \oplus \Z$

magma: MordellWeilGroup(E);

Mordell-Weil generators

$P$	$\hat{h}(P)$	Order
$(-1, 3)$	$0.93845849979430434804516971670$	$\infty$
$(1, 3)$	$1.0178533338050135956553668334$	$\infty$
$(3, 5)$	$1.2955692484043719114722399831$	$\infty$

$\left(-2, 1\right)$ , $\left(-2, 0\right)$ , $\left(-1, 3\right)$ , $\left(-1, -3\right)$ , $\left(0, 3\right)$ , $\left(0, -4\right)$ , $\left(1, 3\right)$ , $\left(1, -5\right)$ , $\left(3, 5\right)$ , $\left(3, -9\right)$ , $\left(4, 7\right)$ , $\left(4, -12\right)$ , $\left(9, 23\right)$ , $\left(9, -33\right)$ , $\left(12, 36\right)$ , $\left(12, -49\right)$ , $\left(15, 51\right)$ , $\left(15, -67\right)$ , $\left(26, 120\right)$ , $\left(26, -147\right)$ , $\left(43, 261\right)$ , $\left(43, -305\right)$ , $\left(55, 381\right)$ , $\left(55, -437\right)$ , $\left(186, 2445\right)$ , $\left(186, -2632\right)$ , $\left(265, 4183\right)$ , $\left(265, -4449\right)$ , $\left(531, 11973\right)$ , $\left(531, -12505\right)$ (-2, 1), (-2, 0), (-1, 3), (-1, -3), (0, 3), (0, -4), (1, 3), (1, -5), (3, 5), (3, -9), (4, 7), (4, -12), (9, 23), (9, -33), (12, 36), (12, -49), (15, 51), (15, -67), (26, 120), (26, -147), (43, 261), (43, -305), (55, 381), (55, -437), (186, 2445), (186, -2632), (265, 4183), (265, -4449), (531, 11973), (531, -12505)

comment: Integral points

sage: E.integral_points()

magma: IntegralPoints(E);

Invariants

Conductor:	$N$	=	$31814$	=	$2 \cdot 15907$	comment: Conductor sage: E.conductor().factor() gp: ellglobalred(E)[1] magma: Conductor(E); oscar: conductor(E)
Discriminant:	$\Delta$	=	$-63628$	=	$-1 \cdot 2^{2} \cdot 15907$	comment: Discriminant sage: E.discriminant().factor() gp: E.disc magma: Discriminant(E); oscar: discriminant(E)
j-invariant:	$j$	=	$\frac{1685159}{63628}$	=	$2^{-2} \cdot 7^{3} \cdot 17^{3} \cdot 15907^{-1}$	comment: j-invariant sage: E.j_invariant().factor() gp: E.j magma: jInvariant(E); oscar: j_invariant(E)
Endomorphism ring:	$\mathrm{End}(E)$	=	$\Z$
Geometric endomorphism ring:	$\mathrm{End}(E_{\overline{\Q}})$	=	$\Z$ (no potential complex multiplication)			sage: E.has_cm() magma: HasComplexMultiplication(E);
Sato-Tate group:	$\mathrm{ST}(E)$	=	$\mathrm{SU}(2)$
Faltings height:	$h_{\mathrm{Faltings}}$	≈	$-0.39838047800450585805893483546$			gp: ellheight(E) magma: FaltingsHeight(E); oscar: faltings_height(E)
Stable Faltings height:	$h_{\mathrm{stable}}$	≈	$-0.39838047800450585805893483546$			magma: StableFaltingsHeight(E); oscar: stable_faltings_height(E)
$abc$ quality:	$Q$	≈	$0.7262290590930661$
Szpiro ratio:	$\sigma_{m}$	≈	$1.7844026908976405$

BSD invariants

Analytic rank:	$r_{\mathrm{an}}$	=	$3$	sage: E.analytic_rank() gp: ellanalyticrank(E) magma: AnalyticRank(E);
Mordell-Weil rank:	$r$	=	$3$	comment: Rank sage: E.rank() gp: [lower,upper] = ellrank(E) magma: Rank(E);
Regulator:	$\mathrm{Reg}(E/\Q)$	≈	$0.88306019809114896025352746205$	comment: Regulator sage: E.regulator() G = E.gen \\ if available matdet(ellheightmatrix(E,G)) magma: Regulator(E);
Real period:	$\Omega$	≈	$2.6415376732824197906735278245$	comment: Real Period sage: E.period_lattice().omega() gp: if(E.disc>0,2,1)E.omega[1] magma: (Discriminant(E) gt 0 select 2 else 1) RealPeriod(E);
Tamagawa product:	$\prod_{p}c_p$	=	$2$ = $2\cdot1$	comment: Tamagawa numbers sage: E.tamagawa_numbers() gp: gr=ellglobalred(E); [[gr[4][i,1],gr[5][i][4]] \| i<-[1..#gr[4][,1]]] magma: TamagawaNumbers(E); oscar: tamagawa_numbers(E)
Torsion order:	$\#E(\Q)_{\mathrm{tor}}$	=	$1$	comment: Torsion order sage: E.torsion_order() gp: elltors(E)[1] magma: Order(TorsionSubgroup(E)); oscar: prod(torsion_structure(E)[1])
Special value:	$L^{(3)}(E,1)/3!$	≈	$4.6652735620680126853229974528$	comment: Special L-value r = E.rank(); E.lseries().dokchitser().derivative(1,r)/r.factorial() gp: [r,L1r] = ellanalyticrank(E); L1r/r! magma: Lr1 where r,Lr1 := AnalyticRank(E: Precision:=12);
Analytic order of Ш:	Ш ${}_{\mathrm{an}}$	≈	$1$ (rounded)	comment: Order of Sha sage: E.sha().an_numerical() magma: MordellWeilShaInformation(E);

BSD formula

$\displaystyle 4.665273562 \approx L^{(3)}(E,1)/3! \overset{?}{=} \frac{\# Ш(E/\Q)\cdot \Omega_E \cdot \mathrm{Reg}(E/\Q) \cdot \prod_p c_p}{\#E(\Q)_{\rm tor}^2} \approx \frac{1 \cdot 2.641538 \cdot 0.883060 \cdot 2}{1^2} \approx 4.665273562$

# self-contained SageMath code snippet for the BSD formula (checks rank, computes analytic sha)

E = EllipticCurve(%s); r = E.rank(); ar = E.analytic_rank(); assert r == ar;

Lr1 = E.lseries().dokchitser().derivative(1,r)/r.factorial(); sha = E.sha().an_numerical();

omega = E.period_lattice().omega(); reg = E.regulator(); tam = E.tamagawa_product(); tor = E.torsion_order();

assert r == ar; print("analytic sha: " + str(RR(Lr1) * tor^2 / (omega * reg * tam)))

/* self-contained Magma code snippet for the BSD formula (checks rank, computes analytic sha) */

E := EllipticCurve(%s); r := Rank(E); ar,Lr1 := AnalyticRank(E: Precision := 12); assert r eq ar;

sha := MordellWeilShaInformation(E); omega := RealPeriod(E) * (Discriminant(E) gt 0 select 2 else 1);

reg := Regulator(E); tam := &*TamagawaNumbers(E); tor := #TorsionSubgroup(E);

assert r eq ar; print "analytic sha:", Lr1 * tor^2 / (omega * reg * tam);

Modular invariants

Modular form 31814.2.a.a

q - q^{2} - 2 q^{3} + q^{4} - 4 q^{5} + 2 q^{6} - 4 q^{7} - q^{8} + q^{9} + 4 q^{10} - 2 q^{11} - 2 q^{12} - 4 q^{13} + 4 q^{14} + 8 q^{15} + q^{16} - q^{18} - 4 q^{19} + O(q^{20})

comment: q-expansion of modular form

sage: E.q_eigenform(20)

\\ actual modular form, use for small N

[mf,F] = mffromell(E)

Ser(mfcoefs(mf,20),q)

\\ or just the series

Ser(ellan(E,20),q)*q

magma: ModularForm(E);

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

Modular degree:	5808	comment: Modular degree sage: E.modular_degree() gp: ellmoddegree(E) magma: ModularDegree(E);
$\Gamma_0(N)$ -optimal:	yes
Manin constant:	1	comment: Manin constant magma: ManinConstant(E);

Local data at primes of bad reduction

This elliptic curve is semistable. There are 2 primes $p$ of bad reduction:

$p$	Tamagawa number	Kodaira symbol	Reduction type	Root number	$\mathrm{ord}_p(N)$	$\mathrm{ord}_p(\Delta)$	$\mathrm{ord}_p(\mathrm{den}(j))$
$2$	$2$	$I_{2}$	nonsplit multiplicative	1	1	2	2
$15907$	$1$	$I_{1}$	nonsplit multiplicative	1	1	1	1

comment: Local data

sage: E.local_data()

gp: ellglobalred(E)[5]

magma: [LocalInformation(E,p) : p in BadPrimes(E)];

oscar: [(p,tamagawa_number(E,p), kodaira_symbol(E,p), reduction_type(E,p)) for p in bad_primes(E)]

Galois representations

The $\ell$ -adic Galois representation has maximal image for all primes $\ell$ .

comment: mod p Galois image

sage: rho = E.galois_representation(); [rho.image_type(p) for p in rho.non_surjective()]

magma: [GaloisRepresentation(E,p): p in PrimesUpTo(20)];

gens = [[1, 1, 31813, 0], [15909, 2, 15909, 3], [1, 0, 2, 1], [1, 2, 0, 1], [31813, 2, 31812, 3]]

GL(2,Integers(31814)).subgroup(gens)

Gens := [[1, 1, 31813, 0], [15909, 2, 15909, 3], [1, 0, 2, 1], [1, 2, 0, 1], [31813, 2, 31812, 3]];

sub<GL(2,Integers(31814))|Gens>;

The image $H:=\rho_E(\Gal(\overline{\Q}/\Q))$ of the adelic Galois representation has level $31814 = 2 \cdot 15907$ , index $2$ , genus $0$ , and generators

$\left(\begin{array}{rr} 1 & 1 \\ 31813 & 0 \end{array}\right),\left(\begin{array}{rr} 15909 & 2 \\ 15909 & 3 \end{array}\right),\left(\begin{array}{rr} 1 & 0 \\ 2 & 1 \end{array}\right),\left(\begin{array}{rr} 1 & 2 \\ 0 & 1 \end{array}\right),\left(\begin{array}{rr} 31813 & 2 \\ 31812 & 3 \end{array}\right)$ .

The torsion field $K:=\Q(E[31814])$ is a degree- $192064488649778448$ Galois extension of $\Q$ with $\Gal(K/\Q)$ isomorphic to the projection of $H$ to $\GL_2(\Z/31814\Z)$ .

The table below list all primes $\ell$ for which the Serre invariants associated to the mod- $\ell$ Galois representation are exceptional.

$\ell$	Reduction type	Serre weight	Serre conductor
$2$	nonsplit multiplicative	$4$	$15907$
$15907$	nonsplit multiplicative	$15908$	$2$

Isogenies

gp: ellisomat(E)

This curve has no rational isogenies. Its isogeny class 31814a consists of this curve only.

Twists

This elliptic curve is its own minimal quadratic twist.

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 $E(\Q)_{\rm tors}$ (which is trivial) are as follows:

$[K:\Q]$	$K$	$E(K)_{\rm tors}$	Base change curve
$3$	3.1.15907.1	$\Z/2\Z$	not in database
$6$	6.0.4024990347643.1	$\Z/2\Z \oplus \Z/2\Z$	not in database
$8$	deg 8	$\Z/3\Z$	not in database
$12$	deg 12	$\Z/4\Z$	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.

Iwasawa invariants

$p$	2	3	5	7	11	13	17	19	23	29	31	37	41	43	47	15907
Reduction type	nonsplit	ord	ord	ord	ord	ord	ss	ord	ord	ord	ord	ord	ord	ord	ord	nonsplit
$\lambda$ -invariant(s)	3	3	7	3	3	3	3,3	3	3	3	3	3	5	3	3	?
$\mu$ -invariant(s)	0	0	0	0	0	0	0,0	0	0	0	0	0	0	0	0	?

An entry ? indicates that the invariants have not yet been computed.

$p$ -adic regulators

Note: $p$ -adic regulator data only exists for primes $p\ge 5$ of good ordinary reduction.

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Minimal Weierstrass equation

Minimal Weierstrass equation

Simplified equation

Mordell-Weil group structure

Mordell-Weil generators

Integral points

Invariants

BSD invariants

BSD formula

Modular invariants

Local data at primes of bad reduction

Galois representations

Isogenies

Twists

Growth of torsion in number fields

Iwasawa invariants

$p$ -adic regulators

This project is supported by grants from the US National Science Foundation, the UK Engineering and Physical Sciences Research Council, and the Simons Foundation.

Label	31814a1

Conductor	$31814$
Discriminant	$-63628$
j-invariant	$\frac{1685159}{63628}$
CM	no
Rank	$3$
Torsion structure	trivial

Properties

Related objects

Downloads

Learn more

Mordell-Weil group structure

Invariants

Local data at primes of bad reduction

Growth of torsion in number fields

ppp-adic regulators

This project is supported by grants from the US National Science Foundation, the UK Engineering and Physical Sciences Research Council, and the Simons Foundation.

$p$ -adic regulators