Curve name | $X_{16}$ | |||||||||
Index | $6$ | |||||||||
Level | $8$ | |||||||||
Genus | $0$ | |||||||||
Does the subgroup contain $-I$? | Yes | |||||||||
Generating matrices | $ \left[ \begin{matrix} 1 & 1 \\ 0 & 1 \end{matrix}\right], \left[ \begin{matrix} 7 & 0 \\ 0 & 1 \end{matrix}\right], \left[ \begin{matrix} 5 & 0 \\ 2 & 1 \end{matrix}\right]$ | |||||||||
Images in lower levels |
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Meaning/Special name | Elliptic curves with a cyclic $4$-isogeny defined over $\mathbb{Q}(\sqrt{2})$ | |||||||||
Chosen covering | $X_{6}$ | |||||||||
Curves that $X_{16}$ minimally covers | $X_{6}$ | |||||||||
Curves that minimally cover $X_{16}$ | $X_{29}$, $X_{38}$, $X_{40}$, $X_{42}$ | |||||||||
Curves that minimally cover $X_{16}$ and have infinitely many rational points. | $X_{29}$, $X_{38}$, $X_{40}$, $X_{42}$ | |||||||||
Model | \[\mathbb{P}^{1}, \mathbb{Q}(X_{16}) = \mathbb{Q}(f_{16}), f_{6} = -2f_{16}^{2} + 48\] | |||||||||
Info about rational points | None | |||||||||
Comments on finding rational points | None | |||||||||
Elliptic curve whose $2$-adic image is the subgroup | $y^2 + xy + y = x^3 + 4x - 6$, with conductor $14$ | |||||||||
Generic density of odd order reductions | $5123/21504$ |