Invariants
Level: | $20$ | $\SL_2$-level: | $4$ | ||||
Index: | $12$ | $\PSL_2$-index: | $12$ | ||||
Genus: | $0 = 1 + \frac{ 12 }{12} - \frac{ 0 }{4} - \frac{ 0 }{3} - \frac{ 4 }{2}$ | ||||||
Cusps: | $4$ (of which $2$ are rational) | Cusp widths | $2^{2}\cdot4^{2}$ | Cusp orbits | $1^{2}\cdot2$ | ||
Elliptic points: | $0$ of order $2$ and $0$ of order $3$ | ||||||
$\Q$-gonality: | $1$ | ||||||
$\overline{\Q}$-gonality: | $1$ | ||||||
Rational cusps: | $2$ | ||||||
Rational CM points: | none |
Other labels
Cummins and Pauli (CP) label: | 4E0 |
Rouse, Sutherland, and Zureick-Brown (RSZB) label: | 20.12.0.8 |
Level structure
$\GL_2(\Z/20\Z)$-generators: | $\begin{bmatrix}5&12\\6&7\end{bmatrix}$, $\begin{bmatrix}5&12\\13&15\end{bmatrix}$, $\begin{bmatrix}7&0\\2&1\end{bmatrix}$ |
Contains $-I$: | yes |
Quadratic refinements: | 20.24.0-20.h.1.1, 20.24.0-20.h.1.2, 40.24.0-20.h.1.1, 40.24.0-20.h.1.2, 40.24.0-20.h.1.3, 40.24.0-20.h.1.4, 40.24.0-20.h.1.5, 40.24.0-20.h.1.6, 60.24.0-20.h.1.1, 60.24.0-20.h.1.2, 120.24.0-20.h.1.1, 120.24.0-20.h.1.2, 120.24.0-20.h.1.3, 120.24.0-20.h.1.4, 120.24.0-20.h.1.5, 120.24.0-20.h.1.6, 140.24.0-20.h.1.1, 140.24.0-20.h.1.2, 220.24.0-20.h.1.1, 220.24.0-20.h.1.2, 260.24.0-20.h.1.1, 260.24.0-20.h.1.2, 280.24.0-20.h.1.1, 280.24.0-20.h.1.2, 280.24.0-20.h.1.3, 280.24.0-20.h.1.4, 280.24.0-20.h.1.5, 280.24.0-20.h.1.6 |
Cyclic 20-isogeny field degree: | $6$ |
Cyclic 20-torsion field degree: | $48$ |
Full 20-torsion field degree: | $3840$ |
Models
This modular curve is isomorphic to $\mathbb{P}^1$.
Rational points
This modular curve has infinitely many rational points, including 480 stored non-cuspidal points.
Maps to other modular curves
$j$-invariant map of degree 12 to the modular curve $X(1)$ :
$\displaystyle j$ | $=$ | $\displaystyle \frac{2^6}{5}\cdot\frac{x^{12}(11x^{4}+192x^{3}y-4736x^{2}y^{2}+12288xy^{3}+45056y^{4})^{3}}{x^{12}(x-8y)^{2}(x+8y)^{2}(3x^{2}-32xy+192y^{2})^{4}}$ |
Modular covers
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.
Covered curve | Level | Index | Degree | Genus | Rank |
---|---|---|---|---|---|
$X_0(4)$ | $4$ | $2$ | $2$ | $0$ | $0$ |
20.6.0.a.1 | $20$ | $2$ | $2$ | $0$ | $0$ |
20.6.0.e.1 | $20$ | $2$ | $2$ | $0$ | $0$ |
This modular curve is minimally covered by the modular curves in the database listed below.
Covering curve | Level | Index | Degree | Genus |
---|---|---|---|---|
20.60.4.l.1 | $20$ | $5$ | $5$ | $4$ |
20.72.3.p.1 | $20$ | $6$ | $6$ | $3$ |
20.120.7.t.1 | $20$ | $10$ | $10$ | $7$ |
40.24.0.bm.1 | $40$ | $2$ | $2$ | $0$ |
40.24.0.bn.1 | $40$ | $2$ | $2$ | $0$ |
40.24.0.bw.1 | $40$ | $2$ | $2$ | $0$ |
40.24.0.bx.1 | $40$ | $2$ | $2$ | $0$ |
60.36.2.t.1 | $60$ | $3$ | $3$ | $2$ |
60.48.1.l.1 | $60$ | $4$ | $4$ | $1$ |
120.24.0.cq.1 | $120$ | $2$ | $2$ | $0$ |
120.24.0.cr.1 | $120$ | $2$ | $2$ | $0$ |
120.24.0.cy.1 | $120$ | $2$ | $2$ | $0$ |
120.24.0.cz.1 | $120$ | $2$ | $2$ | $0$ |
140.96.5.l.1 | $140$ | $8$ | $8$ | $5$ |
140.252.16.t.1 | $140$ | $21$ | $21$ | $16$ |
140.336.21.t.1 | $140$ | $28$ | $28$ | $21$ |
180.324.22.bb.1 | $180$ | $27$ | $27$ | $22$ |
220.144.9.l.1 | $220$ | $12$ | $12$ | $9$ |
260.168.11.p.1 | $260$ | $14$ | $14$ | $11$ |
280.24.0.ce.1 | $280$ | $2$ | $2$ | $0$ |
280.24.0.cf.1 | $280$ | $2$ | $2$ | $0$ |
280.24.0.ci.1 | $280$ | $2$ | $2$ | $0$ |
280.24.0.cj.1 | $280$ | $2$ | $2$ | $0$ |