LMFDB - Elliptic curve with Cremona label 7935b8 (LMFDB label 7935.d3)

Show commands: Magma / Oscar / PariGP / SageMath

Simplified equation

$y^2+xy+y=x^3+x^2-58201x+10122788$ y^2+xy+y=x^3+x^2-58201x+10122788	(homogenize, simplify)
$y^2z+xyz+yz^2=x^3+x^2z-58201xz^2+10122788z^3$ y^2z+xyz+yz^2=x^3+x^2z-58201xz^2+10122788z^3	(dehomogenize, simplify)
$y^2=x^3-75428523x+473420233062$ y^2=x^3-75428523x+473420233062	(homogenize, minimize)

comment: Define the curve

sage: E = EllipticCurve([1, 1, 1, -58201, 10122788])

gp: E = ellinit([1, 1, 1, -58201, 10122788])

magma: E := EllipticCurve([1, 1, 1, -58201, 10122788]);

oscar: E = elliptic_curve([1, 1, 1, -58201, 10122788])

sage: E.short_weierstrass_model()

magma: WeierstrassModel(E);

oscar: short_weierstrass_model(E)

Mordell-Weil generators

$P$	$\hat{h}(P)$	Order
$(-1213/4, 1209/8)$	$0$	$2$

Integral points

None

comment: Integral points

sage: E.integral_points()

magma: IntegralPoints(E);

Invariants

Conductor:	$N$	=	$7935$	=	$3 \cdot 5 \cdot 23^{2}$	comment: Conductor sage: E.conductor().factor() gp: ellglobalred(E)[1] magma: Conductor(E); oscar: conductor(E)
Discriminant:	$\Delta$	=	$-31862298058849845$	=	$-1 \cdot 3^{16} \cdot 5 \cdot 23^{6}$	comment: Discriminant sage: E.discriminant().factor() gp: E.disc magma: Discriminant(E); oscar: discriminant(E)
j-invariant:	$j$	=	$-\frac{147281603041}{215233605}$	=	$-1 \cdot 3^{-16} \cdot 5^{-1} \cdot 5281^{3}$	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:	$h_{\mathrm{Faltings}}$	≈	$1.8586167164416763673770120402$			gp: ellheight(E) magma: FaltingsHeight(E); oscar: faltings_height(E)
Stable Faltings height:	$h_{\mathrm{stable}}$	≈	$0.29086960847710152197363562430$			magma: StableFaltingsHeight(E); oscar: stable_faltings_height(E)
$abc$ quality:	$Q$	≈	$1.0594919023465201$
Szpiro ratio:	$\sigma_{m}$	≈	$5.0994914182446465$

BSD invariants

Analytic rank:	$r_{\mathrm{an}}$	=	$0$	sage: E.analytic_rank() gp: ellanalyticrank(E) magma: AnalyticRank(E);
Mordell-Weil rank:	$r$	=	$0$	comment: Rank sage: E.rank() gp: [lower,upper] = ellrank(E) magma: Rank(E);
Regulator:	$\mathrm{Reg}(E/\Q)$	=	$1$	comment: Regulator sage: E.regulator() G = E.gen \\ if available matdet(ellheightmatrix(E,G)) magma: Regulator(E);
Real period:	$\Omega$	≈	$0.33283951164097181539858884969$	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:	$\prod_{p}c_p$	=	$8$ = $2\cdot1\cdot2^{2}$	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:	$\#E(\Q)_{\mathrm{tor}}$	=	$2$	comment: Torsion order sage: E.torsion_order() gp: elltors(E)[1] magma: Order(TorsionSubgroup(E)); oscar: prod(torsion_structure(E)[1])
Special value:	$L(E,1)$	≈	$0.66567902328194363079717769939$	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 ${}_{\mathrm{an}}$	=	$1$ (exact)	comment: Order of Sha sage: E.sha().an_numerical() magma: MordellWeilShaInformation(E);

$\displaystyle 0.665679023 \approx L(E,1) = \frac{\# Ш(E/\Q)\cdot \Omega_E \cdot \mathrm{Reg}(E/\Q) \cdot \prod_p c_p}{\#E(\Q)_{\rm tor}^2} \approx \frac{1 \cdot 0.332840 \cdot 1.000000 \cdot 8}{2^2} \approx 0.665679023$

# 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 7935.2.a.d

q - q^{2} - q^{3} - q^{4} - q^{5} + q^{6} + 3 q^{8} + q^{9} + q^{10} + 4 q^{11} + q^{12} - 2 q^{13} + q^{15} - q^{16} - 2 q^{17} - 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:	50688	comment: Modular degree sage: E.modular_degree() gp: ellmoddegree(E) magma: ModularDegree(E);
$\Gamma_0(N)$ -optimal:	no
Manin constant:	1	comment: Manin constant magma: ManinConstant(E);

Local data at primes of bad reduction

This elliptic curve is not semistable. There are 3 primes $p$ of bad reduction:

$p$	Tamagawa number	Kodaira symbol	Reduction type	Root number	$\mathrm{ord}_p(N)$	$\mathrm{ord}_p(\Delta)$	$\mathrm{ord}_p(\mathrm{den}(j))$
$3$	$2$	$I_{16}$	nonsplit multiplicative	1	1	16	16
$5$	$1$	$I_{1}$	nonsplit multiplicative	1	1	1	1
$23$	$4$	$I_0^{*}$	additive	-1	2	6	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
$2$	2B	16.48.0.134

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 = [[23, 18, 8478, 9035], [1, 0, 32, 1], [7361, 1472, 2576, 1473], [1174, 483, 10925, 9868], [5820, 8671, 1679, 4164], [4319, 0, 0, 11039], [5, 28, 68, 381], [1381, 1472, 7636, 1473], [11009, 32, 11008, 33], [1, 32, 0, 1]]

GL(2,Integers(11040)).subgroup(gens)

Gens := [[23, 18, 8478, 9035], [1, 0, 32, 1], [7361, 1472, 2576, 1473], [1174, 483, 10925, 9868], [5820, 8671, 1679, 4164], [4319, 0, 0, 11039], [5, 28, 68, 381], [1381, 1472, 7636, 1473], [11009, 32, 11008, 33], [1, 32, 0, 1]];

sub<GL(2,Integers(11040))|Gens>;

The image $H:=\rho_E(\Gal(\overline{\Q}/\Q))$ of the adelic Galois representation has level $11040 = 2^{5} \cdot 3 \cdot 5 \cdot 23$ , index $768$ , genus $13$ , and generators

$\left(\begin{array}{rr} 23 & 18 \\ 8478 & 9035 \end{array}\right),\left(\begin{array}{rr} 1 & 0 \\ 32 & 1 \end{array}\right),\left(\begin{array}{rr} 7361 & 1472 \\ 2576 & 1473 \end{array}\right),\left(\begin{array}{rr} 1174 & 483 \\ 10925 & 9868 \end{array}\right),\left(\begin{array}{rr} 5820 & 8671 \\ 1679 & 4164 \end{array}\right),\left(\begin{array}{rr} 4319 & 0 \\ 0 & 11039 \end{array}\right),\left(\begin{array}{rr} 5 & 28 \\ 68 & 381 \end{array}\right),\left(\begin{array}{rr} 1381 & 1472 \\ 7636 & 1473 \end{array}\right),\left(\begin{array}{rr} 11009 & 32 \\ 11008 & 33 \end{array}\right),\left(\begin{array}{rr} 1 & 32 \\ 0 & 1 \end{array}\right)$ .

The torsion field $K:=\Q(E[11040])$ is a degree- $3151641968640$ Galois extension of $\Q$ with $\Gal(K/\Q)$ isomorphic to the projection of $H$ to $\GL_2(\Z/11040\Z)$ .

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
$2$	good	$2$	$2645 = 5 \cdot 23^{2}$
$3$	nonsplit multiplicative	$4$	$2645 = 5 \cdot 23^{2}$
$5$	nonsplit multiplicative	$6$	$1587 = 3 \cdot 23^{2}$
$23$	additive	$266$	$15 = 3 \cdot 5$

Isogenies

gp: ellisomat(E)

This curve has non-trivial cyclic isogenies of degree $d$ for $d=$ 2, 4, 8 and 16.
Its isogeny class 7935b consists of 8 curves linked by isogenies of degrees dividing 16.

Twists

The minimal quadratic twist of this elliptic curve is 15a6, its twist by $-23$ .

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:

$[K:\Q]$	$K$	$E(K)_{\rm tors}$	Base change curve
$2$	$\Q(\sqrt{-5})$	$\Z/2\Z \oplus \Z/2\Z$	not in database
$2$	$\Q(\sqrt{23})$	$\Z/4\Z$	not in database
$2$	$\Q(\sqrt{-115})$	$\Z/4\Z$	not in database
$4$	$\Q(\sqrt{-5}, \sqrt{23})$	$\Z/2\Z \oplus \Z/4\Z$	not in database
$4$	$\Q(\sqrt{10}, \sqrt{23})$	$\Z/8\Z$	not in database
$4$	$\Q(\sqrt{-2}, \sqrt{23})$	$\Z/8\Z$	not in database
$8$	8.0.286557184000000.6	$\Z/2\Z \oplus \Z/4\Z$	not in database
$8$	8.0.1119364000000.5	$\Z/8\Z$	not in database
$8$	8.0.11462287360000.6	$\Z/2\Z \oplus \Z/8\Z$	not in database
$8$	8.8.73358639104000000.2	$\Z/16\Z$	not in database
$8$	8.0.73358639104000000.4	$\Z/16\Z$	not in database
$8$	deg 8	$\Z/6\Z$	not in database
$16$	deg 16	$\Z/4\Z \oplus \Z/4\Z$	not in database
$16$	deg 16	$\Z/2\Z \oplus \Z/8\Z$	not in database
$16$	deg 16	$\Z/16\Z$	not in database
$16$	deg 16	$\Z/16\Z$	not in database
$16$	16.0.5381489931190917922816000000000000.6	$\Z/2\Z \oplus \Z/16\Z$	not in database
$16$	deg 16	$\Z/2\Z \oplus \Z/6\Z$	not in database
$16$	deg 16	$\Z/12\Z$	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.

Iwasawa invariants

$p$	2	3	5	23
Reduction type	ord	nonsplit	nonsplit	add
$\lambda$ -invariant(s)	4	0	0	-
$\mu$ -invariant(s)	1	0	0	-

All Iwasawa $\lambda$ and $\mu$ -invariants for primes $p\ge 3$ of good reduction are zero.

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

$p$ -adic regulators

All $p$ -adic regulators are identically $1$ since the rank is $0$ .

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Introduction

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Database

Properties

Related objects

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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	7935b8

Conductor	$7935$
Discriminant	$-3.186\times 10^{16}$
j-invariant	$-\frac{147281603041}{215233605}$
CM	no
Rank	$0$
Torsion structure	$\Z/{2}\Z$

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