Properties

Label 50.a3
Conductor 5050
Discriminant 1250-1250
j-invariant 252 -\frac{25}{2}
CM no
Rank 00
Torsion structure Z/3Z\Z/{3}\Z

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Minimal Weierstrass equation

Minimal Weierstrass equation

Simplified equation

y2+xy+y=x3x2y^2+xy+y=x^3-x-2 Copy content Toggle raw display (homogenize, simplify)
y2z+xyz+yz2=x3xz22z3y^2z+xyz+yz^2=x^3-xz^2-2z^3 Copy content Toggle raw display (dehomogenize, simplify)
y2=x3675x79650y^2=x^3-675x-79650 Copy content Toggle raw display (homogenize, minimize)

comment: Define the curve
 
sage: E = EllipticCurve([1, 0, 1, -1, -2])
 
gp: E = ellinit([1, 0, 1, -1, -2])
 
magma: E := EllipticCurve([1, 0, 1, -1, -2]);
 
oscar: E = elliptic_curve([1, 0, 1, -1, -2])
 
sage: E.short_weierstrass_model()
 
magma: WeierstrassModel(E);
 
oscar: short_weierstrass_model(E)
 

Mordell-Weil group structure

Z/3Z\Z/{3}\Z

magma: MordellWeilGroup(E);
 

Mordell-Weil generators

PPh^(P)\hat{h}(P)Order
(2,1)(2, 1)0033

Integral points

(2,1) \left(2, 1\right) , (2,4) \left(2, -4\right) Copy content Toggle raw display

comment: Integral points
 
sage: E.integral_points()
 
magma: IntegralPoints(E);
 

Invariants

Conductor: NN  =  50 50  = 2522 \cdot 5^{2}
comment: Conductor
 
sage: E.conductor().factor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
oscar: conductor(E)
 
Discriminant: Δ\Delta  =  1250-1250 = 1254-1 \cdot 2 \cdot 5^{4}
comment: Discriminant
 
sage: E.discriminant().factor()
 
gp: E.disc
 
magma: Discriminant(E);
 
oscar: discriminant(E)
 
j-invariant: jj  =  252 -\frac{25}{2}  = 12152-1 \cdot 2^{-1} \cdot 5^{2}
comment: j-invariant
 
sage: E.j_invariant().factor()
 
gp: E.j
 
magma: jInvariant(E);
 
oscar: j_invariant(E)
 
Endomorphism ring: End(E)\mathrm{End}(E) = Z\Z
Geometric endomorphism ring: End(EQ)\mathrm{End}(E_{\overline{\Q}})  =  Z\Z    (no potential complex multiplication)
sage: E.has_cm()
 
magma: HasComplexMultiplication(E);
 
Sato-Tate group: ST(E)\mathrm{ST}(E) = SU(2)\mathrm{SU}(2)
Faltings height: hFaltingsh_{\mathrm{Faltings}} ≈ 0.72609959614388153275382537999-0.72609959614388153275382537999
gp: ellheight(E)
 
magma: FaltingsHeight(E);
 
oscar: faltings_height(E)
 
Stable Faltings height: hstableh_{\mathrm{stable}} ≈ 1.2625789002885816576207451577-1.2625789002885816576207451577
magma: StableFaltingsHeight(E);
 
oscar: stable_faltings_height(E)
 
abcabc quality: QQ ≈ 1.09043509069626741.0904350906962674
Szpiro ratio: σm\sigma_{m} ≈ 3.7302506956885213.730250695688521

BSD invariants

Analytic rank: ranr_{\mathrm{an}} = 0 0
sage: E.analytic_rank()
 
gp: ellanalyticrank(E)
 
magma: AnalyticRank(E);
 
Mordell-Weil rank: rr = 0 0
comment: Rank
 
sage: E.rank()
 
gp: [lower,upper] = ellrank(E)
 
magma: Rank(E);
 
Regulator: Reg(E/Q)\mathrm{Reg}(E/\Q) = 11
comment: Regulator
 
sage: E.regulator()
 
G = E.gen \\ if available
 
matdet(ellheightmatrix(E,G))
 
magma: Regulator(E);
 
Real period: Ω\Omega ≈ 2.13949494428489026801580397012.1394949442848902680158039701
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: pcp\prod_{p}c_p = 3 3  = 13 1\cdot3
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)tor\#E(\Q)_{\mathrm{tor}} = 33
comment: Torsion order
 
sage: E.torsion_order()
 
gp: elltors(E)[1]
 
magma: Order(TorsionSubgroup(E));
 
oscar: prod(torsion_structure(E)[1])
 
Special value: L(E,1) L(E,1) ≈ 0.713164981428296756005267990030.71316498142829675600526799003
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: Шan{}_{\mathrm{an}}  =  11    (exact)
comment: Order of Sha
 
sage: E.sha().an_numerical()
 
magma: MordellWeilShaInformation(E);
 

BSD formula

0.713164981L(E,1)=#Ш(E/Q)ΩEReg(E/Q)pcp#E(Q)tor212.1394951.0000003320.713164981\displaystyle 0.713164981 \approx L(E,1) = \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 2.139495 \cdot 1.000000 \cdot 3}{3^2} \approx 0.713164981

# 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   50.2.a.a

qq2+q3+q4q6+2q7q82q93q11+q124q132q14+q163q17+2q18+5q19+O(q20) q - q^{2} + q^{3} + q^{4} - q^{6} + 2 q^{7} - q^{8} - 2 q^{9} - 3 q^{11} + q^{12} - 4 q^{13} - 2 q^{14} + q^{16} - 3 q^{17} + 2 q^{18} + 5 q^{19} + O(q^{20}) Copy content Toggle raw display

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: 2
comment: Modular degree
 
sage: E.modular_degree()
 
gp: ellmoddegree(E)
 
magma: ModularDegree(E);
 
Γ0(N) \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 not semistable. There are 2 primes pp of bad reduction:

pp Tamagawa number Kodaira symbol Reduction type Root number ordp(N)\mathrm{ord}_p(N) ordp(Δ)\mathrm{ord}_p(\Delta) ordp(den(j))\mathrm{ord}_p(\mathrm{den}(j))
22 11 I1I_{1} nonsplit multiplicative 1 1 1 1
55 33 IVIV additive -1 2 4 0

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 except those listed in the table below.

prime \ell mod-\ell image \ell-adic image
22 2G 8.2.0.1
33 3B.1.1 3.8.0.1
55 5B.1.3 5.24.0.4

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 = [[46, 105, 45, 1], [1, 42, 90, 61], [1, 0, 60, 1], [81, 10, 40, 81], [31, 90, 15, 91], [1, 72, 0, 1], [41, 80, 40, 81], [61, 90, 45, 91], [1, 0, 30, 1], [73, 90, 0, 49], [1, 36, 60, 1]]
 
GL(2,Integers(120)).subgroup(gens)
 
Gens := [[46, 105, 45, 1], [1, 42, 90, 61], [1, 0, 60, 1], [81, 10, 40, 81], [31, 90, 15, 91], [1, 72, 0, 1], [41, 80, 40, 81], [61, 90, 45, 91], [1, 0, 30, 1], [73, 90, 0, 49], [1, 36, 60, 1]];
 
sub<GL(2,Integers(120))|Gens>;
 

The image H:=ρE(Gal(Q/Q))H:=\rho_E(\Gal(\overline{\Q}/\Q)) of the adelic Galois representation has level 120=2335 120 = 2^{3} \cdot 3 \cdot 5 , index 384384, genus 99, and generators

(46105451),(1429061),(10601),(81104081),(31901591),(17201),(41804081),(61904591),(10301),(7390049),(136601)\left(\begin{array}{rr} 46 & 105 \\ 45 & 1 \end{array}\right),\left(\begin{array}{rr} 1 & 42 \\ 90 & 61 \end{array}\right),\left(\begin{array}{rr} 1 & 0 \\ 60 & 1 \end{array}\right),\left(\begin{array}{rr} 81 & 10 \\ 40 & 81 \end{array}\right),\left(\begin{array}{rr} 31 & 90 \\ 15 & 91 \end{array}\right),\left(\begin{array}{rr} 1 & 72 \\ 0 & 1 \end{array}\right),\left(\begin{array}{rr} 41 & 80 \\ 40 & 81 \end{array}\right),\left(\begin{array}{rr} 61 & 90 \\ 45 & 91 \end{array}\right),\left(\begin{array}{rr} 1 & 0 \\ 30 & 1 \end{array}\right),\left(\begin{array}{rr} 73 & 90 \\ 0 & 49 \end{array}\right),\left(\begin{array}{rr} 1 & 36 \\ 60 & 1 \end{array}\right).

Input positive integer mm to see the generators of the reduction of HH to GL2(Z/mZ)\mathrm{GL}_2(\Z/m\Z):

The torsion field K:=Q(E[120])K:=\Q(E[120]) is a degree-9216092160 Galois extension of Q\Q with Gal(K/Q)\Gal(K/\Q) isomorphic to the projection of HH to GL2(Z/120Z)\GL_2(\Z/120\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
22 nonsplit multiplicative 44 25=52 25 = 5^{2}
55 additive 1414 2 2

Isogenies

gp: ellisomat(E)
 

This curve has non-trivial cyclic isogenies of degree dd for d=d= 3, 5 and 15.
Its isogeny class 50.a consists of 4 curves linked by isogenies of degrees dividing 15.

Twists

This elliptic curve is its own minimal quadratic twist.

Growth of torsion in number fields

The number fields KK of degree less than 24 such that E(K)torsE(K)_{\rm tors} is strictly larger than E(Q)torsE(\Q)_{\rm tors} Z/3Z\cong \Z/{3}\Z are as follows:

[K:Q][K:\Q] KK E(K)torsE(K)_{\rm tors} Base change curve
33 3.1.200.1 Z/6Z\Z/6\Z not in database
44 Q(ζ5)\Q(\zeta_{5}) Z/15Z\Z/15\Z not in database
66 6.0.320000.1 Z/2ZZ/6Z\Z/2\Z \oplus \Z/6\Z not in database
66 6.0.270000.1 Z/3ZZ/3Z\Z/3\Z \oplus \Z/3\Z not in database
99 9.3.4920750000.1 Z/9Z\Z/9\Z not in database
1010 10.2.12500000000.1 Z/15Z\Z/15\Z not in database
1212 12.2.52428800000000.3 Z/12Z\Z/12\Z not in database
1212 12.0.200000000000.1 Z/30Z\Z/30\Z not in database
1818 18.0.322486272000000000000.1 Z/3ZZ/6Z\Z/3\Z \oplus \Z/6\Z not in database
2020 20.0.781250000000000000000.1 Z/5ZZ/15Z\Z/5\Z \oplus \Z/15\Z not in database

We only show fields where the torsion growth is primitive.

Iwasawa invariants

pp 2 3 5
Reduction type nonsplit ord add
λ\lambda-invariant(s) 2 2 -
μ\mu-invariant(s) 0 0 -

All Iwasawa λ\lambda and μ\mu-invariants for primes p7p\ge 7 of good reduction are zero.

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

pp-adic regulators

All pp-adic regulators are identically 11 since the rank is 00.

Additional information

This curve EE also has a double cover by Bring's curve BP4:i=15xi=i=15xi2=i=15xi3=0 B \subset {\bf P}^4: \sum_{i=1}^5 x_i = \sum_{i=1}^5 x_i^2 = \sum_{i=1}^5 x_i^3 = 0 of genus 44. Indeed BB has automorphisms by S5S_5 (permuting the projective coordinates xix_i), and the quotient by a simple transposition σS5\sigma \in S_5 is EE. The 33-cycles that commute with σ\sigma act on BB by translation by the 33-torsion points of EE.