Minimal Weierstrass equation
Minimal Weierstrass equation
Simplified equation
| \(y^2=x^3+x^2-81x-561\) | (homogenize, simplify) | 
| \(y^2z=x^3+x^2z-81xz^2-561z^3\) | (dehomogenize, simplify) | 
| \(y^2=x^3-6588x-389232\) | (homogenize, minimize) | 
Mordell-Weil group structure
\(\Z/{2}\Z\)
Mordell-Weil generators
| $P$ | $\hat{h}(P)$ | Order | 
|---|---|---|
| $(11, 0)$ | $0$ | $2$ | 
Integral points
      
    \( \left(11, 0\right) \)
    
    
    
        
    
    
        
    
      
Invariants
| Conductor: | $N$ | = | \( 18240 \) | = | $2^{6} \cdot 3 \cdot 5 \cdot 19$ |  | 
| Discriminant: | $\Delta$ | = | $-88719360$ | = | $-1 \cdot 2^{14} \cdot 3 \cdot 5 \cdot 19^{2} $ |  | 
| j-invariant: | $j$ | = | \( -\frac{3631696}{5415} \) | = | $-1 \cdot 2^{4} \cdot 3^{-1} \cdot 5^{-1} \cdot 19^{-2} \cdot 61^{3}$ |  | 
| Endomorphism ring: | $\mathrm{End}(E)$ | = | $\Z$ | |||
| Geometric endomorphism ring: | $\mathrm{End}(E_{\overline{\Q}})$ | = | \(\Z\) (no potential complex multiplication) |  | ||
| Sato-Tate group: | $\mathrm{ST}(E)$ | = | $\mathrm{SU}(2)$ | |||
| Faltings height: | $h_{\mathrm{Faltings}}$ | ≈ | $0.21683835471890873850849858484$ |  | ||
| Stable Faltings height: | $h_{\mathrm{stable}}$ | ≈ | $-0.59183335593436078914493889019$ |  | ||
| $abc$ quality: | $Q$ | ≈ | $0.788354479109591$ | |||
| Szpiro ratio: | $\sigma_{m}$ | ≈ | $2.6585129036424666$ | |||
BSD invariants
| Analytic rank: | $r_{\mathrm{an}}$ | = | $ 0$ |  | 
| Mordell-Weil rank: | $r$ | = | $ 0$ |  | 
| Regulator: | $\mathrm{Reg}(E/\Q)$ | = | $1$ |  | 
| Real period: | $\Omega$ | ≈ | $0.75473623516488652297057823345$ |  | 
| Tamagawa product: | $\prod_{p}c_p$ | = | $ 8 $ = $ 2^{2}\cdot1\cdot1\cdot2 $ |  | 
| Torsion order: | $\#E(\Q)_{\mathrm{tor}}$ | = | $2$ |  | 
| Special value: | $ L(E,1)$ | ≈ | $1.5094724703297730459411564669 $ |  | 
| Analytic order of Ш: | Ш${}_{\mathrm{an}}$ | = | $1$ (exact) |  | 
BSD formula
$$\begin{aligned} 1.509472470 \approx L(E,1) & = \frac{\# ะจ(E/\Q)\cdot \Omega_E \cdot \mathrm{Reg}(E/\Q) \cdot \prod_p c_p}{\#E(\Q)_{\rm tor}^2} \\ & \approx \frac{1 \cdot 0.754736 \cdot 1.000000 \cdot 8}{2^2} \\ & \approx 1.509472470\end{aligned}$$
Modular invariants
For more coefficients, see the Downloads section to the right.
| Modular degree: | 6144 |  | 
| $ \Gamma_0(N) $-optimal: | yes | |
| Manin constant: | 1 |  | 
Local data at primes of bad reduction
This elliptic curve is not semistable. There are 4 primes $p$ of bad reduction:
| $p$ | Tamagawa number | Kodaira symbol | Reduction type | Root number | $\mathrm{ord}_p(N)$ | $\mathrm{ord}_p(\Delta)$ | $\mathrm{ord}_p(\mathrm{den}(j))$ | 
|---|---|---|---|---|---|---|---|
| $2$ | $4$ | $I_{4}^{*}$ | additive | 1 | 6 | 14 | 0 | 
| $3$ | $1$ | $I_{1}$ | split multiplicative | -1 | 1 | 1 | 1 | 
| $5$ | $1$ | $I_{1}$ | nonsplit multiplicative | 1 | 1 | 1 | 1 | 
| $19$ | $2$ | $I_{2}$ | nonsplit multiplicative | 1 | 1 | 2 | 2 | 
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 | 2.3.0.1 | 
The image $H:=\rho_E(\Gal(\overline{\Q}/\Q))$ of the adelic Galois representation has level \( 1140 = 2^{2} \cdot 3 \cdot 5 \cdot 19 \), index $12$, genus $0$, and generators
$\left(\begin{array}{rr} 781 & 4 \\ 422 & 9 \end{array}\right),\left(\begin{array}{rr} 1 & 2 \\ 2 & 5 \end{array}\right),\left(\begin{array}{rr} 1 & 4 \\ 0 & 1 \end{array}\right),\left(\begin{array}{rr} 289 & 856 \\ 284 & 855 \end{array}\right),\left(\begin{array}{rr} 1137 & 4 \\ 1136 & 5 \end{array}\right),\left(\begin{array}{rr} 1 & 0 \\ 4 & 1 \end{array}\right),\left(\begin{array}{rr} 382 & 1 \\ 379 & 0 \end{array}\right),\left(\begin{array}{rr} 3 & 4 \\ 8 & 11 \end{array}\right),\left(\begin{array}{rr} 914 & 1 \\ 683 & 0 \end{array}\right)$.
The torsion field $K:=\Q(E[1140])$ is a degree-$22693478400$ Galois extension of $\Q$ with $\Gal(K/\Q)$ isomorphic to the projection of $H$ to $\GL_2(\Z/1140\Z)$.
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 | 
|---|---|---|---|
| $2$ | additive | $2$ | \( 15 = 3 \cdot 5 \) | 
| $3$ | split multiplicative | $4$ | \( 6080 = 2^{6} \cdot 5 \cdot 19 \) | 
| $5$ | nonsplit multiplicative | $6$ | \( 3648 = 2^{6} \cdot 3 \cdot 19 \) | 
| $19$ | nonsplit multiplicative | $20$ | \( 960 = 2^{6} \cdot 3 \cdot 5 \) | 
Isogenies
This curve has non-trivial cyclic isogenies of degree $d$ for $d=$
2.
Its isogeny class 18240.bz
consists of 2 curves linked by isogenies of
degree 2.
Twists
The minimal quadratic twist of this elliptic curve is 2280.d2, its twist by $8$.
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:
| $[K:\Q]$ | $K$ | $E(K)_{\rm tors}$ | Base change curve | 
|---|---|---|---|
| $2$ | \(\Q(\sqrt{-15}) \) | \(\Z/2\Z \oplus \Z/2\Z\) | not in database | 
| $4$ | 4.2.1386240.2 | \(\Z/4\Z\) | not in database | 
| $8$ | 8.0.432373800960000.69 | \(\Z/2\Z \oplus \Z/4\Z\) | not in database | 
| $8$ | 8.0.16842816000000.88 | \(\Z/2\Z \oplus \Z/4\Z\) | not in database | 
| $8$ | deg 8 | \(\Z/6\Z\) | not in database | 
| $16$ | deg 16 | \(\Z/8\Z\) | not in database | 
| $16$ | deg 16 | \(\Z/2\Z \oplus \Z/6\Z\) | 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 | 19 | 
|---|---|---|---|---|
| Reduction type | add | split | nonsplit | nonsplit | 
| $\lambda$-invariant(s) | - | 1 | 0 | 0 | 
| $\mu$-invariant(s) | - | 0 | 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 $0$.
