Invariants
| Level: | $28$ | $\SL_2$-level: | $4$ | ||||
| Index: | $12$ | $\PSL_2$-index: | $6$ | ||||
| Genus: | $0 = 1 + \frac{ 6 }{12} - \frac{ 0 }{4} - \frac{ 0 }{3} - \frac{ 3 }{2}$ | ||||||
| Cusps: | $3$ (all of which are rational) | Cusp widths | $1^{2}\cdot4$ | Cusp orbits | $1^{3}$ | ||
| Elliptic points: | $0$ of order $2$ and $0$ of order $3$ | ||||||
| $\Q$-gonality: | $1$ | ||||||
| $\overline{\Q}$-gonality: | $1$ | ||||||
| Rational cusps: | $3$ | ||||||
| Rational CM points: | yes $\quad(D =$ $-4,-16$) |
Other labels
| Cummins and Pauli (CP) label: | 4B0 |
| Rouse, Sutherland, and Zureick-Brown (RSZB) label: | 28.12.0.8 |
Level structure
| $\GL_2(\Z/28\Z)$-generators: | $\begin{bmatrix}2&19\\25&12\end{bmatrix}$, $\begin{bmatrix}13&8\\2&11\end{bmatrix}$, $\begin{bmatrix}15&4\\24&3\end{bmatrix}$ |
| Contains $-I$: | no $\quad$ (see 4.6.0.c.1 for the level structure with $-I$) |
| Cyclic 28-isogeny field degree: | $8$ |
| Cyclic 28-torsion field degree: | $96$ |
| Full 28-torsion field degree: | $16128$ |
Models
This modular curve is isomorphic to $\mathbb{P}^1$.
Rational points
This modular curve has infinitely many rational points, including 95098 stored non-cuspidal points.
Maps to other modular curves
$j$-invariant map of degree 6 to the modular curve $X(1)$ :
| $\displaystyle j$ | $=$ | $\displaystyle \frac{x^{6}(48x^{2}-y^{2})^{3}}{x^{10}(8x-y)(8x+y)}$ |
Modular covers
This modular curve is minimally covered by the modular curves in the database listed below.
| Covering curve | Level | Index | Degree | Genus |
|---|---|---|---|---|
| 28.24.0-4.b.1.3 | $28$ | $2$ | $2$ | $0$ |
| 28.24.0-4.d.1.1 | $28$ | $2$ | $2$ | $0$ |
| 56.24.0-8.d.1.2 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-8.k.1.2 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-8.m.1.3 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-8.m.1.6 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-8.n.1.5 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-8.n.1.10 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-8.o.1.3 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-8.o.1.6 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-8.p.1.3 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-8.p.1.6 | $56$ | $2$ | $2$ | $0$ |
| 84.24.0-12.g.1.2 | $84$ | $2$ | $2$ | $0$ |
| 84.24.0-12.h.1.2 | $84$ | $2$ | $2$ | $0$ |
| 84.36.1-12.c.1.1 | $84$ | $3$ | $3$ | $1$ |
| 84.48.0-12.g.1.8 | $84$ | $4$ | $4$ | $0$ |
| 140.24.0-20.g.1.2 | $140$ | $2$ | $2$ | $0$ |
| 140.24.0-20.h.1.2 | $140$ | $2$ | $2$ | $0$ |
| 140.60.2-20.c.1.2 | $140$ | $5$ | $5$ | $2$ |
| 140.72.1-20.c.1.5 | $140$ | $6$ | $6$ | $1$ |
| 140.120.3-20.c.1.5 | $140$ | $10$ | $10$ | $3$ |
| 168.24.0-24.s.1.2 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-24.v.1.3 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-24.y.1.4 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-24.y.1.13 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-24.z.1.8 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-24.z.1.9 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-24.ba.1.8 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-24.ba.1.9 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-24.bb.1.4 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-24.bb.1.13 | $168$ | $2$ | $2$ | $0$ |
| 28.24.0-28.g.1.2 | $28$ | $2$ | $2$ | $0$ |
| 28.24.0-28.h.1.1 | $28$ | $2$ | $2$ | $0$ |
| 28.96.2-28.c.1.8 | $28$ | $8$ | $8$ | $2$ |
| 28.252.7-28.c.1.8 | $28$ | $21$ | $21$ | $7$ |
| 28.336.9-28.c.1.6 | $28$ | $28$ | $28$ | $9$ |
| 252.324.10-36.d.1.4 | $252$ | $27$ | $27$ | $10$ |
| 280.24.0-40.s.1.4 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-40.v.1.3 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-40.y.1.7 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-40.y.1.10 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-40.z.1.5 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-40.z.1.12 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-40.ba.1.5 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-40.ba.1.12 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-40.bb.1.7 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-40.bb.1.10 | $280$ | $2$ | $2$ | $0$ |
| 308.24.0-44.g.1.2 | $308$ | $2$ | $2$ | $0$ |
| 308.24.0-44.h.1.2 | $308$ | $2$ | $2$ | $0$ |
| 308.144.4-44.c.1.7 | $308$ | $12$ | $12$ | $4$ |
| 56.24.0-56.s.1.3 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-56.v.1.3 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-56.y.1.1 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-56.y.1.16 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-56.z.1.2 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-56.z.1.15 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-56.ba.1.2 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-56.ba.1.15 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-56.bb.1.1 | $56$ | $2$ | $2$ | $0$ |
| 56.24.0-56.bb.1.16 | $56$ | $2$ | $2$ | $0$ |
| 84.24.0-84.g.1.4 | $84$ | $2$ | $2$ | $0$ |
| 84.24.0-84.h.1.3 | $84$ | $2$ | $2$ | $0$ |
| 140.24.0-140.g.1.4 | $140$ | $2$ | $2$ | $0$ |
| 140.24.0-140.h.1.4 | $140$ | $2$ | $2$ | $0$ |
| 168.24.0-168.s.1.4 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-168.v.1.2 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-168.y.1.15 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-168.y.1.18 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-168.z.1.7 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-168.z.1.26 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-168.ba.1.7 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-168.ba.1.26 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-168.bb.1.15 | $168$ | $2$ | $2$ | $0$ |
| 168.24.0-168.bb.1.18 | $168$ | $2$ | $2$ | $0$ |
| 280.24.0-280.s.1.6 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-280.v.1.7 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-280.y.1.2 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-280.y.1.31 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-280.z.1.4 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-280.z.1.29 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-280.ba.1.4 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-280.ba.1.29 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-280.bb.1.2 | $280$ | $2$ | $2$ | $0$ |
| 280.24.0-280.bb.1.31 | $280$ | $2$ | $2$ | $0$ |
| 308.24.0-308.g.1.4 | $308$ | $2$ | $2$ | $0$ |
| 308.24.0-308.h.1.3 | $308$ | $2$ | $2$ | $0$ |