Curve name | $X_{19}$ | |||||||||
Index | $6$ | |||||||||
Level | $8$ | |||||||||
Genus | $0$ | |||||||||
Does the subgroup contain $-I$? | Yes | |||||||||
Generating matrices | $ \left[ \begin{matrix} 1 & 0 \\ 2 & 1 \end{matrix}\right], \left[ \begin{matrix} 1 & 0 \\ 0 & 3 \end{matrix}\right], \left[ \begin{matrix} 1 & 1 \\ 0 & 5 \end{matrix}\right]$ | |||||||||
Images in lower levels |
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Meaning/Special name | Elliptic curves that acquire full $2$-torsion over $\mathbb{Q}(\sqrt{-2})$ | |||||||||
Chosen covering | $X_{6}$ | |||||||||
Curves that $X_{19}$ minimally covers | $X_{4}$, $X_{6}$ | |||||||||
Curves that minimally cover $X_{19}$ | $X_{29}$, $X_{48}$ | |||||||||
Curves that minimally cover $X_{19}$ and have infinitely many rational points. | $X_{29}$, $X_{48}$ | |||||||||
Model | \[\mathbb{P}^{1}, \mathbb{Q}(X_{19}) = \mathbb{Q}(f_{19}), f_{6} = \frac{48f_{19}^{2} - 32}{f_{19}^{2} + 2}\] | |||||||||
Info about rational points | None | |||||||||
Comments on finding rational points | None | |||||||||
Elliptic curve whose $2$-adic image is the subgroup | $y^2 + xy + y = x^3 + 4x + 20$, with conductor $66$ | |||||||||
Generic density of odd order reductions | $5123/21504$ |