$\GL_2(\Z/40\Z)$-generators: |
$\begin{bmatrix}5&4\\8&1\end{bmatrix}$, $\begin{bmatrix}19&8\\36&35\end{bmatrix}$, $\begin{bmatrix}27&26\\36&1\end{bmatrix}$, $\begin{bmatrix}37&38\\20&7\end{bmatrix}$ |
Contains $-I$: |
yes |
Quadratic refinements: |
40.384.5-40.a.1.1, 40.384.5-40.a.1.2, 40.384.5-40.a.1.3, 40.384.5-40.a.1.4, 40.384.5-40.a.1.5, 40.384.5-40.a.1.6, 40.384.5-40.a.1.7, 40.384.5-40.a.1.8, 80.384.5-40.a.1.1, 80.384.5-40.a.1.2, 80.384.5-40.a.1.3, 80.384.5-40.a.1.4, 120.384.5-40.a.1.1, 120.384.5-40.a.1.2, 120.384.5-40.a.1.3, 120.384.5-40.a.1.4, 120.384.5-40.a.1.5, 120.384.5-40.a.1.6, 120.384.5-40.a.1.7, 120.384.5-40.a.1.8, 240.384.5-40.a.1.1, 240.384.5-40.a.1.2, 240.384.5-40.a.1.3, 240.384.5-40.a.1.4, 280.384.5-40.a.1.1, 280.384.5-40.a.1.2, 280.384.5-40.a.1.3, 280.384.5-40.a.1.4, 280.384.5-40.a.1.5, 280.384.5-40.a.1.6, 280.384.5-40.a.1.7, 280.384.5-40.a.1.8 |
Cyclic 40-isogeny field degree: |
$12$ |
Cyclic 40-torsion field degree: |
$192$ |
Full 40-torsion field degree: |
$3840$ |
Canonical model in $\mathbb{P}^{ 4 }$ defined by 3 equations
$ 0 $ | $=$ | $ 2 x^{2} + y^{2} + z^{2} $ |
| $=$ | $5 y^{2} - 5 z^{2} - t^{2}$ |
| $=$ | $10 y z - w^{2}$ |
Singular plane model Singular plane model
$ 0 $ | $=$ | $ 625 x^{8} - 1000 x^{6} z^{2} + 50 x^{4} y^{4} + 1400 x^{4} z^{4} - 40 x^{2} y^{4} z^{2} - 800 x^{2} z^{6} + \cdots + 144 z^{8} $ |
This modular curve has no real points and no $\Q_p$ points for $p=29$, and therefore no rational points.
Maps between models of this curve
Birational map from canonical model to plane model:
$\displaystyle X$ |
$=$ |
$\displaystyle x+y$ |
$\displaystyle Y$ |
$=$ |
$\displaystyle w$ |
$\displaystyle Z$ |
$=$ |
$\displaystyle \frac{1}{2}t$ |
Maps to other modular curves
Map
of degree 2 from the canonical model of this modular curve to the canonical model of the modular curve
40.96.3.t.1
:
$\displaystyle X$ |
$=$ |
$\displaystyle -x$ |
$\displaystyle Y$ |
$=$ |
$\displaystyle 2x+w$ |
$\displaystyle Z$ |
$=$ |
$\displaystyle 2x+t$ |
Equation of the image curve:
$0$ |
$=$ |
$ 68X^{4}-32X^{3}Y-24X^{2}Y^{2}-8XY^{3}-Y^{4}-32X^{3}Z-24X^{2}Z^{2}-8XZ^{3}-Z^{4} $ |
Hi
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Cover information
Click on a modular curve in the diagram to see information about it.
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This modular curve minimally covers the modular curves listed below.
This modular curve is minimally covered by the modular curves in the database listed below.