Properties

Label 21840.b
Number of curves $4$
Conductor $21840$
CM no
Rank $0$
Graph

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Show commands: SageMath
E = EllipticCurve("b1")
 
E.isogeny_class()
 

Elliptic curves in class 21840.b

sage: E.isogeny_class().curves
 
LMFDB label Cremona label Weierstrass coefficients j-invariant Discriminant Torsion structure Modular degree Faltings height Optimality
21840.b1 21840x4 \([0, -1, 0, -410066496, -3196016968704]\) \(1861772567578966373029167169/9401133413380800000\) \(38507042461207756800000\) \([2]\) \(4423680\) \(3.5319\)  
21840.b2 21840x2 \([0, -1, 0, -26066496, -48138568704]\) \(478202393398338853167169/32244226560000000000\) \(132072351989760000000000\) \([2, 2]\) \(2211840\) \(3.1853\)  
21840.b3 21840x1 \([0, -1, 0, -5094976, 3518479360]\) \(3571003510905229697089/762141946675200000\) \(3121733413581619200000\) \([2]\) \(1105920\) \(2.8387\) \(\Gamma_0(N)\)-optimal
21840.b4 21840x3 \([0, -1, 0, 22389184, -206646789120]\) \(303025056761573589385151/4678857421875000000000\) \(-19164600000000000000000000\) \([2]\) \(4423680\) \(3.5319\)  

Rank

sage: E.rank()
 

The elliptic curves in class 21840.b have rank \(0\).

Complex multiplication

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

Modular form 21840.2.a.b

sage: E.q_eigenform(10)
 
\(q - q^{3} - q^{5} - q^{7} + q^{9} - q^{13} + q^{15} + 2 q^{17} - 4 q^{19} + O(q^{20})\) 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 LMFDB numbering.

\(\left(\begin{array}{rrrr} 1 & 2 & 4 & 4 \\ 2 & 1 & 2 & 2 \\ 4 & 2 & 1 & 4 \\ 4 & 2 & 4 & 1 \end{array}\right)\)

Isogeny graph

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

The vertices are labelled with LMFDB labels.