Properties

Label 21840bf
Number of curves $4$
Conductor $21840$
CM no
Rank $1$
Graph

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Show commands: SageMath
E = EllipticCurve("bf1")
 
E.isogeny_class()
 

Elliptic curves in class 21840bf

sage: E.isogeny_class().curves
 
LMFDB label Cremona label Weierstrass coefficients j-invariant Discriminant Torsion structure Modular degree Faltings height Optimality
21840.a3 21840bf1 \([0, -1, 0, -12136, 235120]\) \(48264326765929/22299191460\) \(91337488220160\) \([2]\) \(82944\) \(1.3735\) \(\Gamma_0(N)\)-optimal
21840.a4 21840bf2 \([0, -1, 0, 42744, 1727856]\) \(2108526614950391/1540302022350\) \(-6309077083545600\) \([2]\) \(165888\) \(1.7200\)  
21840.a1 21840bf3 \([0, -1, 0, -823576, 287950576]\) \(15082569606665230489/7751016000\) \(31748161536000\) \([2]\) \(248832\) \(1.9228\)  
21840.a2 21840bf4 \([0, -1, 0, -819096, 291233520]\) \(-14837772556740428569/342100087875000\) \(-1401241959936000000\) \([2]\) \(497664\) \(2.2694\)  

Rank

sage: E.rank()
 

The elliptic curves in class 21840bf have rank \(1\).

Complex multiplication

The elliptic curves in class 21840bf do not have complex multiplication.

Modular form 21840.2.a.bf

sage: E.q_eigenform(10)
 
\(q - q^{3} - q^{5} - q^{7} + q^{9} - 6 q^{11} + q^{13} + q^{15} - 8 q^{19} + O(q^{20})\) Copy content Toggle raw display

Isogeny matrix

sage: E.isogeny_class().matrix()
 

The \(i,j\) entry is the smallest degree of a cyclic isogeny between the \(i\)-th and \(j\)-th curve in the isogeny class, in the Cremona numbering.

\(\left(\begin{array}{rrrr} 1 & 2 & 3 & 6 \\ 2 & 1 & 6 & 3 \\ 3 & 6 & 1 & 2 \\ 6 & 3 & 2 & 1 \end{array}\right)\)

Isogeny graph

sage: E.isogeny_graph().plot(edge_labels=True)
 

The vertices are labelled with Cremona labels.