Elliptic curve with Cremona label 11858bk5 (LMFDB label 11858.bm2)

• Label: 11858bk5
• Conductor: 11858
• Discriminant: -382456734842355712
• j-invariant: \( -\frac{548347731625}{1835008} \)
• CM: no
• Rank: 0
• Torsion Structure: \(\Z/{2}\Z\)

Minimal Weierstrass equation

\( y^2 + x y + y = x^{3} + x^{2} - 1011018 x - 392829865 \)

Mordell-Weil group structure

\(\Z/{2}\Z\)

Torsion generators

\( \left(1161, -581\right) \)

Integral points

\( \left(1161, -581\right) \)

Invariants

Conductor:	\( 11858 \)	=	\(2 \cdot 7^{2} \cdot 11^{2}\)
Discriminant:	\(-382456734842355712 \)	=	\(-1 \cdot 2^{18} \cdot 7^{7} \cdot 11^{6} \)
j-invariant:	\( -\frac{548347731625}{1835008} \)	=	\(-1 \cdot 2^{-18} \cdot 5^{3} \cdot 7^{-1} \cdot 1637^{3}\)
Endomorphism ring:	\(\Z\)		(no Complex Multiplication)
Sato-Tate Group:	$\mathrm{SU}(2)$

BSD invariants

Rank:	\(0\)
Regulator:	\(1\)
Real period:	\(0.075264957159\)
Tamagawa product:	\( 288 \)  = \( ( 2 \cdot 3^{2} )\cdot2^{2}\cdot2^{2} \)
Torsion order:	\(2\)
Analytic order of Ш:	\(1\) (exact)

Modular invariants

Modular form 11858.2.a.bm

\( q + q^{2} + 2q^{3} + q^{4} + 2q^{6} + q^{8} + q^{9} + 2q^{12} - 4q^{13} + q^{16} + 6q^{17} + q^{18} + 2q^{19} + O(q^{20}) \)

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

Modular degree:	207360
\( \Gamma_0(N) \)-optimal:	no
Manin constant:	1

Special L-value

\( L(E,1) \) ≈ \( 5.41907691545 \)

Local data

This elliptic curve is not semistable.

prime	Tamagawa number	Kodaira symbol	Reduction type	Root number	ord(\(N\))	ord(\(\Delta\))	ord\((j)_{-}\)
\(2\)	\(18\)	\( I_{18} \)	Split multiplicative	-1	1	18	18
\(7\)	\(4\)	\( I_1^{*} \)	Additive	-1	2	7	1
\(11\)	\(4\)	\( I_0^{*} \)	Additive	-1	2	6	0

Galois representations

The image of the 2-adic representation attached to this elliptic curve is the subgroup of $\GL(2,\Z_2)$ with Rouse label X16.

This subgroup is the pull-back of the subgroup of $\GL(2,\Z_2/2^3\Z_2)$ generated by $\left(\begin{array}{rr} 1 & 1 \\ 0 & 1 \end{array}\right),\left(\begin{array}{rr} 7 & 0 \\ 0 & 1 \end{array}\right),\left(\begin{array}{rr} 5 & 0 \\ 2 & 1 \end{array}\right)$ and has index 6.

The mod \( p \) Galois representation has maximal image \(\GL(2,\F_p)\) for all primes \( p \) except those listed.

prime	Image of Galois representation
\(2\)	B
\(3\)	B

$p$-adic data

$p$-adic regulators

All \(p\)-adic regulators are identically \(1\) since the rank is \(0\).

Iwasawa invariants

$p$	2	3	7	11
Reduction type	split	ordinary	add	add
$\lambda$-invariant(s)	4	0	-	-
$\mu$-invariant(s)	0	2	-	-

All Iwasawa $\lambda$ and $\mu$-invariants for primes $p\ge 5$ of good reduction are zero.

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

Isogenies

This curve has non-trivial cyclic isogenies of degree \(d\) for \(d=\) 2, 3, 6, 9 and 18.
Its isogeny class 11858bk consists of 6 curves linked by isogenies of degrees dividing 18.

Growth of torsion in number fields

The number fields $K$ of degree up to 7 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	\(\Q(\sqrt{-7}) \)	\(\Z/2\Z \times \Z/2\Z\)	Not in database
	\(\Q(\sqrt{-231}) \)	\(\Z/6\Z\)	Not in database
4	\(\Q(\sqrt{-7}, \sqrt{33})\)	\(\Z/2\Z \times \Z/6\Z\)	Not in database
	4.2.54208.3	\(\Z/4\Z\)	Not in database
6	6.2.16307815293.1	\(\Z/6\Z\)	Not in database
	6.0.440311012911.5	\(\Z/18\Z\)	Not in database

We only show fields where the torsion growth is primitive. For each field $K$ we either show its label, or a defining polynomial when $K$ is not in the database.