Properties

Label 4080k1
Conductor 40804080
Discriminant 110160110160
j-invariant 2126295046885 \frac{212629504}{6885}
CM no
Rank 00
Torsion structure Z/2Z\Z/{2}\Z

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Minimal Weierstrass equation

Minimal Weierstrass equation

Simplified equation

y2=x3+x231x76y^2=x^3+x^2-31x-76 Copy content Toggle raw display (homogenize, simplify)
y2z=x3+x2z31xz276z3y^2z=x^3+x^2z-31xz^2-76z^3 Copy content Toggle raw display (dehomogenize, simplify)
y2=x32538x47817y^2=x^3-2538x-47817 Copy content Toggle raw display (homogenize, minimize)

comment: Define the curve
 
sage: E = EllipticCurve([0, 1, 0, -31, -76])
 
gp: E = ellinit([0, 1, 0, -31, -76])
 
magma: E := EllipticCurve([0, 1, 0, -31, -76]);
 
oscar: E = elliptic_curve([0, 1, 0, -31, -76])
 
sage: E.short_weierstrass_model()
 
magma: WeierstrassModel(E);
 
oscar: short_weierstrass_model(E)
 

Mordell-Weil group structure

Z/2Z\Z/{2}\Z

magma: MordellWeilGroup(E);
 

Mordell-Weil generators

PPh^(P)\hat{h}(P)Order
(4,0)(-4, 0)0022

Integral points

(4,0) \left(-4, 0\right) Copy content Toggle raw display

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

Invariants

Conductor: NN  =  4080 4080  = 2435172^{4} \cdot 3 \cdot 5 \cdot 17
comment: Conductor
 
sage: E.conductor().factor()
 
gp: ellglobalred(E)[1]
 
magma: Conductor(E);
 
oscar: conductor(E)
 
Discriminant: Δ\Delta  =  110160110160 = 24345172^{4} \cdot 3^{4} \cdot 5 \cdot 17
comment: Discriminant
 
sage: E.discriminant().factor()
 
gp: E.disc
 
magma: Discriminant(E);
 
oscar: discriminant(E)
 
j-invariant: jj  =  2126295046885 \frac{212629504}{6885}  = 21134511714732^{11} \cdot 3^{-4} \cdot 5^{-1} \cdot 17^{-1} \cdot 47^{3}
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}} ≈ 0.25867153852865992408934765983-0.25867153852865992408934765983
gp: ellheight(E)
 
magma: FaltingsHeight(E);
 
oscar: faltings_height(E)
 
Stable Faltings height: hstableh_{\mathrm{stable}} ≈ 0.48972059871530836056175836698-0.48972059871530836056175836698
magma: StableFaltingsHeight(E);
 
oscar: stable_faltings_height(E)
 
abcabc quality: QQ ≈ 0.8549476281163540.854947628116354
Szpiro ratio: σm\sigma_{m} ≈ 2.6398894047702152.639889404770215

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 ≈ 2.02189922850028758983394266642.0218992285002875898339426664
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 = 4 4  = 12211 1\cdot2^{2}\cdot1\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)tor\#E(\Q)_{\mathrm{tor}} = 22
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) ≈ 2.02189922850028758983394266642.0218992285002875898339426664
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

2.021899229L(E,1)=#Ш(E/Q)ΩEReg(E/Q)pcp#E(Q)tor212.0218991.0000004222.021899229\displaystyle 2.021899229 \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 2.021899 \cdot 1.000000 \cdot 4}{2^2} \approx 2.021899229

# 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   4080.2.a.t

q+q3q5+q92q13q15q174q19+O(q20) q + q^{3} - q^{5} + q^{9} - 2 q^{13} - q^{15} - q^{17} - 4 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: 384
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 4 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 IIII additive 1 4 4 0
33 44 I4I_{4} split multiplicative -1 1 4 4
55 11 I1I_{1} nonsplit multiplicative 1 1 1 1
1717 11 I1I_{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 except those listed in the table below.

prime \ell mod-\ell image \ell-adic image
22 2B 4.6.0.1

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 = [[1361, 8, 1364, 33], [7, 6, 2034, 2035], [259, 258, 778, 1795], [1, 0, 8, 1], [1, 8, 0, 1], [1928, 3, 1205, 2], [1, 4, 4, 17], [1271, 1272, 242, 1265], [1228, 1, 431, 6], [2033, 8, 2032, 9]]
 
GL(2,Integers(2040)).subgroup(gens)
 
Gens := [[1361, 8, 1364, 33], [7, 6, 2034, 2035], [259, 258, 778, 1795], [1, 0, 8, 1], [1, 8, 0, 1], [1928, 3, 1205, 2], [1, 4, 4, 17], [1271, 1272, 242, 1265], [1228, 1, 431, 6], [2033, 8, 2032, 9]];
 
sub<GL(2,Integers(2040))|Gens>;
 

The image H:=ρE(Gal(Q/Q))H:=\rho_E(\Gal(\overline{\Q}/\Q)) of the adelic Galois representation has level 2040=233517 2040 = 2^{3} \cdot 3 \cdot 5 \cdot 17 , index 4848, genus 00, and generators

(13618136433),(7620342035),(2592587781795),(1081),(1801),(1928312052),(14417),(127112722421265),(122814316),(2033820329)\left(\begin{array}{rr} 1361 & 8 \\ 1364 & 33 \end{array}\right),\left(\begin{array}{rr} 7 & 6 \\ 2034 & 2035 \end{array}\right),\left(\begin{array}{rr} 259 & 258 \\ 778 & 1795 \end{array}\right),\left(\begin{array}{rr} 1 & 0 \\ 8 & 1 \end{array}\right),\left(\begin{array}{rr} 1 & 8 \\ 0 & 1 \end{array}\right),\left(\begin{array}{rr} 1928 & 3 \\ 1205 & 2 \end{array}\right),\left(\begin{array}{rr} 1 & 4 \\ 4 & 17 \end{array}\right),\left(\begin{array}{rr} 1271 & 1272 \\ 242 & 1265 \end{array}\right),\left(\begin{array}{rr} 1228 & 1 \\ 431 & 6 \end{array}\right),\left(\begin{array}{rr} 2033 & 8 \\ 2032 & 9 \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[2040])K:=\Q(E[2040]) is a degree-5775556608057755566080 Galois extension of Q\Q with Gal(K/Q)\Gal(K/\Q) isomorphic to the projection of HH to GL2(Z/2040Z)\GL_2(\Z/2040\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 additive 22 85=517 85 = 5 \cdot 17
33 split multiplicative 44 1360=24517 1360 = 2^{4} \cdot 5 \cdot 17
55 nonsplit multiplicative 66 816=24317 816 = 2^{4} \cdot 3 \cdot 17
1717 nonsplit multiplicative 1818 240=2435 240 = 2^{4} \cdot 3 \cdot 5

Isogenies

gp: ellisomat(E)
 

This curve has non-trivial cyclic isogenies of degree dd for d=d= 2 and 4.
Its isogeny class 4080k consists of 4 curves linked by isogenies of degrees dividing 4.

Twists

The minimal quadratic twist of this elliptic curve is 2040a1, its twist by 4-4.

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/2Z\cong \Z/{2}\Z are as follows:

[K:Q][K:\Q] KK E(K)torsE(K)_{\rm tors} Base change curve
22 Q(85)\Q(\sqrt{85}) Z/2ZZ/2Z\Z/2\Z \oplus \Z/2\Z not in database
22 Q(5)\Q(\sqrt{-5}) Z/4Z\Z/4\Z not in database
22 Q(17)\Q(\sqrt{-17}) Z/4Z\Z/4\Z not in database
44 Q(5,17)\Q(\sqrt{-5}, \sqrt{-17}) Z/2ZZ/4Z\Z/2\Z \oplus \Z/4\Z not in database
88 8.4.96550276000000.2 Z/2ZZ/4Z\Z/2\Z \oplus \Z/4\Z not in database
88 8.0.93636000000.11 Z/8Z\Z/8\Z not in database
88 8.0.200206652313600.16 Z/8Z\Z/8\Z not in database
88 deg 8 Z/6Z\Z/6\Z not in database
1616 deg 16 Z/4ZZ/4Z\Z/4\Z \oplus \Z/4\Z not in database
1616 deg 16 Z/2ZZ/8Z\Z/2\Z \oplus \Z/8\Z not in database
1616 deg 16 Z/2ZZ/8Z\Z/2\Z \oplus \Z/8\Z not in database
1616 deg 16 Z/2ZZ/6Z\Z/2\Z \oplus \Z/6\Z not in database
1616 deg 16 Z/12Z\Z/12\Z not in database
1616 deg 16 Z/12Z\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.

Iwasawa invariants

pp 2 3 5 17
Reduction type add split nonsplit nonsplit
λ\lambda-invariant(s) - 3 0 0
μ\mu-invariant(s) - 0 0 0

All Iwasawa λ\lambda and μ\mu-invariants for primes p3p\ge 3 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.