## The modular curve $X_{85l}$

Curve name $X_{85l}$
Index $48$
Level $8$
Genus $0$
Does the subgroup contain $-I$? No
Generating matrices $\left[ \begin{matrix} 5 & 5 \\ 0 & 5 \end{matrix}\right], \left[ \begin{matrix} 1 & 0 \\ 0 & 5 \end{matrix}\right], \left[ \begin{matrix} 1 & 0 \\ 0 & 7 \end{matrix}\right]$
Images in lower levels
 Level Index of image Corresponding curve $2$ $3$ $X_{6}$ $4$ $12$ $X_{13f}$
Meaning/Special name
Chosen covering $X_{85}$
Curves that $X_{85l}$ minimally covers
Curves that minimally cover $X_{85l}$
Curves that minimally cover $X_{85l}$ and have infinitely many rational points.
Model $\mathbb{P}^{1}$, a universal elliptic curve over an appropriate base is given by $y^2 = x^3 + A(t)x + B(t), \text{ where}$ $A(t) = -27t^{8} + 216t^{6} + 1080t^{4} - 6048t^{2} - 432$ $B(t) = -54t^{12} + 648t^{10} - 9720t^{8} + 60480t^{6} - 85536t^{4} - 114048t^{2} + 3456$
Elliptic curve whose $2$-adic image is the subgroup $y^2 + xy = x^3 - 34x - 217$, with conductor $21$
Generic density of odd order reductions $5/84$