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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([0,1]),K([0,1]),K([0,0]),K([46,19]),K([-125,93])]) 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 3456.2-b have rank \( 0 \).

Isogeny matrix

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

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

Isogeny graph

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

Elliptic curves in class 3456.2-b over \(\Q(\sqrt{-2}) \)

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

Isogeny class 3456.2-b contains 4 curves linked by isogenies of degrees dividing 4.

Curve label Weierstrass Coefficients
3456.2-b1 \( \bigl[a\) , \( a\) , \( 0\) , \( 19 a + 46\) , \( 93 a - 125\bigr] \)
3456.2-b2 \( \bigl[a\) , \( a\) , \( 0\) , \( -6 a - 54\) , \( -47 a - 136\bigr] \)
3456.2-b3 \( \bigl[0\) , \( a + 1\) , \( 0\) , \( -12 a + 6\) , \( -18 a + 90\bigr] \)
3456.2-b4 \( \bigl[0\) , \( a + 1\) , \( 0\) , \( -70 a + 35\) , \( 69 a - 345\bigr] \)