Properties

Label 21021b
Number of curves $6$
Conductor $21021$
CM no
Rank $0$
Graph

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

Elliptic curves in class 21021b

sage: E.isogeny_class().curves
 
LMFDB label Cremona label Weierstrass coefficients j-invariant Discriminant Torsion structure Modular degree Faltings height Optimality
21021.e5 21021b1 \([1, 1, 1, -1177, -22786]\) \(-1532808577/938223\) \(-110380997727\) \([2]\) \(24576\) \(0.82090\) \(\Gamma_0(N)\)-optimal
21021.e4 21021b2 \([1, 1, 1, -21022, -1181734]\) \(8732907467857/1656369\) \(194870156481\) \([2, 2]\) \(49152\) \(1.1675\)  
21021.e3 21021b3 \([1, 1, 1, -23227, -921544]\) \(11779205551777/3763454409\) \(442766647764441\) \([2, 2]\) \(98304\) \(1.5141\)  
21021.e1 21021b4 \([1, 1, 1, -336337, -75217696]\) \(35765103905346817/1287\) \(151414263\) \([2]\) \(98304\) \(1.5141\)  
21021.e6 21021b5 \([1, 1, 1, 65708, -6186496]\) \(266679605718863/296110251723\) \(-34837075004959227\) \([2]\) \(196608\) \(1.8606\)  
21021.e2 21021b6 \([1, 1, 1, -147442, 21039668]\) \(3013001140430737/108679952667\) \(12786087751319883\) \([2]\) \(196608\) \(1.8606\)  

Rank

sage: E.rank()
 

The elliptic curves in class 21021b have rank \(0\).

Complex multiplication

The elliptic curves in class 21021b do not have complex multiplication.

Modular form 21021.2.a.b

sage: E.q_eigenform(10)
 
\(q - q^{2} - q^{3} - q^{4} + 2 q^{5} + q^{6} + 3 q^{8} + q^{9} - 2 q^{10} - q^{11} + q^{12} - q^{13} - 2 q^{15} - q^{16} + 6 q^{17} - q^{18} + 4 q^{19} + O(q^{20})\) 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 Cremona numbering.

\(\left(\begin{array}{rrrrrr} 1 & 2 & 4 & 4 & 8 & 8 \\ 2 & 1 & 2 & 2 & 4 & 4 \\ 4 & 2 & 1 & 4 & 2 & 2 \\ 4 & 2 & 4 & 1 & 8 & 8 \\ 8 & 4 & 2 & 8 & 1 & 4 \\ 8 & 4 & 2 & 8 & 4 & 1 \end{array}\right)\)

Isogeny graph

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

The vertices are labelled with Cremona labels.