Curve name | $X_{90}$ | |||||||||
Index | $24$ | |||||||||
Level | $8$ | |||||||||
Genus | $0$ | |||||||||
Does the subgroup contain $-I$? | Yes | |||||||||
Generating matrices | $ \left[ \begin{matrix} 1 & 3 \\ 6 & 7 \end{matrix}\right], \left[ \begin{matrix} 1 & 1 \\ 4 & 3 \end{matrix}\right], \left[ \begin{matrix} 1 & 2 \\ 0 & 5 \end{matrix}\right]$ | |||||||||
Images in lower levels |
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Meaning/Special name | ||||||||||
Chosen covering | $X_{28}$ | |||||||||
Curves that $X_{90}$ minimally covers | $X_{28}$, $X_{39}$, $X_{50}$ | |||||||||
Curves that minimally cover $X_{90}$ | $X_{256}$, $X_{262}$, $X_{280}$, $X_{281}$, $X_{282}$, $X_{283}$, $X_{284}$, $X_{285}$ | |||||||||
Curves that minimally cover $X_{90}$ and have infinitely many rational points. | $X_{281}$, $X_{284}$ | |||||||||
Model | \[\mathbb{P}^{1}, \mathbb{Q}(X_{90}) = \mathbb{Q}(f_{90}), f_{28} = \frac{2f_{90}^{2} - 4}{f_{90}^{2} + 4f_{90} + 2}\] | |||||||||
Info about rational points | None | |||||||||
Comments on finding rational points | None | |||||||||
Elliptic curve whose $2$-adic image is the subgroup | $y^2 = x^3 - 3371423x + 801711878$, with conductor $16940$ | |||||||||
Generic density of odd order reductions | $1427/5376$ |