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Base field \(\Q(\sqrt{2}) \)

Copy content comment:Define the base number field
 
Copy content sage:R.<x> = PolynomialRing(QQ); K.<a> = NumberField(R([-2, 0, 1]))
 
Copy content pari:K = nfinit(Polrev(%s));
 
Copy content magma:R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R!%s);
 
Copy content oscar:Qx, x = polynomial_ring(QQ); K, a = number_field(Qx(%s))
 

Generator \(a\), with minimal polynomial \( x^{2} - 2 \); class number \(1\).

Copy content comment:Define the isogeny class
 
Copy content sage:E = EllipticCurve([K([0,0]),K([0,-1]),K([0,0]),K([-11,10]),K([-30,23])]) E.isogeny_class()
 

Rank

Copy content comment:Compute the Mordell-Weil rank
 
Copy content sage:E.rank()
 
Copy content magma:Rank(E);
 

The elliptic curves in class 256.1-c have rank \( 0 \).

Isogeny matrix

Copy content comment:Isogeny matrix
 
Copy content sage:E.isogeny_class().matrix()
 

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

Isogeny graph

Copy content comment:Isogeny graph
 
Copy content sage:E.isogeny_class().graph().plot(edge_labels=True)
 

Elliptic curves in class 256.1-c over \(\Q(\sqrt{2}) \)

Copy content comment:List of curves in the isogeny class
 
Copy content sage:E.isogeny_class().curves
 

Isogeny class 256.1-c contains 6 curves linked by isogenies of degrees dividing 8.

Curve label Weierstrass Coefficients
256.1-c1 \( \bigl[0\) , \( -a\) , \( 0\) , \( 10 a - 11\) , \( 23 a - 30\bigr] \)
256.1-c2 \( \bigl[0\) , \( a\) , \( 0\) , \( 10 a - 11\) , \( -23 a + 30\bigr] \)
256.1-c3 \( \bigl[0\) , \( -a\) , \( 0\) , \( -1\) , \( a\bigr] \)
256.1-c4 \( \bigl[0\) , \( a\) , \( 0\) , \( -1\) , \( -a\bigr] \)
256.1-c5 \( \bigl[0\) , \( a\) , \( 0\) , \( -10 a - 11\) , \( -23 a - 30\bigr] \)
256.1-c6 \( \bigl[0\) , \( -a\) , \( 0\) , \( -10 a - 11\) , \( 23 a + 30\bigr] \)