Invariants
| Level: | $28$ | $\SL_2$-level: | $28$ | Newform level: | $784$ | ||
| Index: | $672$ | $\PSL_2$-index: | $336$ | ||||
| Genus: | $21 = 1 + \frac{ 336 }{12} - \frac{ 0 }{4} - \frac{ 0 }{3} - \frac{ 16 }{2}$ | ||||||
| Cusps: | $16$ (of which $2$ are rational) | Cusp widths | $14^{8}\cdot28^{8}$ | Cusp orbits | $1^{2}\cdot2\cdot3^{2}\cdot6$ | ||
| Elliptic points: | $0$ of order $2$ and $0$ of order $3$ | ||||||
| Analytic rank: | $4$ | ||||||
| $\Q$-gonality: | $6 \le \gamma \le 12$ | ||||||
| $\overline{\Q}$-gonality: | $6 \le \gamma \le 12$ | ||||||
| Rational cusps: | $2$ | ||||||
| Rational CM points: | none |
Other labels
| Cummins and Pauli (CP) label: | 28D21 |
| Rouse, Sutherland, and Zureick-Brown (RSZB) label: | 28.672.21.40 |
Level structure
| $\GL_2(\Z/28\Z)$-generators: | $\begin{bmatrix}3&13\\0&11\end{bmatrix}$, $\begin{bmatrix}7&3\\4&21\end{bmatrix}$, $\begin{bmatrix}27&5\\12&9\end{bmatrix}$ |
| $\GL_2(\Z/28\Z)$-subgroup: | $C_6^2:D_4$ |
| Contains $-I$: | no $\quad$ (see 28.336.21.t.1 for the level structure with $-I$) |
| Cyclic 28-isogeny field degree: | $2$ |
| Cyclic 28-torsion field degree: | $12$ |
| Full 28-torsion field degree: | $288$ |
Jacobian
| Conductor: | $2^{60}\cdot7^{40}$ |
| Simple: | no |
| Squarefree: | no |
| Decomposition: | $1^{9}\cdot2^{6}$ |
| Newforms: | 14.2.a.a$^{2}$, 98.2.a.b$^{2}$, 196.2.a.b, 196.2.a.c, 784.2.a.b, 784.2.a.c, 784.2.a.e, 784.2.a.g, 784.2.a.i, 784.2.a.j, 784.2.a.k, 784.2.a.l, 784.2.a.m |
Rational points
This modular curve has 2 rational cusps but no known non-cuspidal rational points.
Modular covers
This modular curve minimally covers the modular curves listed below.
| Covered curve | Level | Index | Degree | Genus | Rank | Kernel decomposition |
|---|---|---|---|---|---|---|
| 28.24.0-28.h.1.2 | $28$ | $28$ | $28$ | $0$ | $0$ | full Jacobian |
| 28.336.9-28.c.1.2 | $28$ | $2$ | $2$ | $9$ | $0$ | $1^{6}\cdot2^{3}$ |
| 28.336.9-28.c.1.8 | $28$ | $2$ | $2$ | $9$ | $0$ | $1^{6}\cdot2^{3}$ |
This modular curve is minimally covered by the modular curves in the database listed below.
| Covering curve | Level | Index | Degree | Genus | Rank | Kernel decomposition |
|---|---|---|---|---|---|---|
| 28.1344.41-28.bm.1.1 | $28$ | $2$ | $2$ | $41$ | $10$ | $1^{18}\cdot2$ |
| 28.1344.41-28.bn.1.2 | $28$ | $2$ | $2$ | $41$ | $12$ | $1^{18}\cdot2$ |
| 28.1344.41-28.bu.1.1 | $28$ | $2$ | $2$ | $41$ | $8$ | $1^{18}\cdot2$ |
| 28.1344.41-28.bv.1.1 | $28$ | $2$ | $2$ | $41$ | $12$ | $1^{18}\cdot2$ |
| 28.2016.61-28.bb.1.1 | $28$ | $3$ | $3$ | $61$ | $14$ | $1^{26}\cdot2^{7}$ |
| 56.1344.41-56.kg.1.1 | $56$ | $2$ | $2$ | $41$ | $14$ | $1^{18}\cdot2$ |
| 56.1344.41-56.kn.1.1 | $56$ | $2$ | $2$ | $41$ | $11$ | $1^{18}\cdot2$ |
| 56.1344.41-56.mk.1.1 | $56$ | $2$ | $2$ | $41$ | $10$ | $1^{18}\cdot2$ |
| 56.1344.41-56.mr.1.1 | $56$ | $2$ | $2$ | $41$ | $15$ | $1^{18}\cdot2$ |
| 56.1344.45-56.fg.1.1 | $56$ | $2$ | $2$ | $45$ | $11$ | $1^{12}\cdot2^{6}$ |
| 56.1344.45-56.fg.1.15 | $56$ | $2$ | $2$ | $45$ | $11$ | $1^{12}\cdot2^{6}$ |
| 56.1344.45-56.fh.1.3 | $56$ | $2$ | $2$ | $45$ | $8$ | $1^{12}\cdot2^{6}$ |
| 56.1344.45-56.fh.1.21 | $56$ | $2$ | $2$ | $45$ | $8$ | $1^{12}\cdot2^{6}$ |
| 56.1344.45-56.fw.1.1 | $56$ | $2$ | $2$ | $45$ | $9$ | $1^{20}\cdot2^{2}$ |
| 56.1344.45-56.fw.1.15 | $56$ | $2$ | $2$ | $45$ | $9$ | $1^{20}\cdot2^{2}$ |
| 56.1344.45-56.fx.1.1 | $56$ | $2$ | $2$ | $45$ | $13$ | $1^{20}\cdot2^{2}$ |
| 56.1344.45-56.fx.1.14 | $56$ | $2$ | $2$ | $45$ | $13$ | $1^{20}\cdot2^{2}$ |
| 56.1344.45-56.ga.1.1 | $56$ | $2$ | $2$ | $45$ | $9$ | $1^{20}\cdot2^{2}$ |
| 56.1344.45-56.ga.1.14 | $56$ | $2$ | $2$ | $45$ | $9$ | $1^{20}\cdot2^{2}$ |
| 56.1344.45-56.gb.1.1 | $56$ | $2$ | $2$ | $45$ | $21$ | $1^{20}\cdot2^{2}$ |
| 56.1344.45-56.gb.1.15 | $56$ | $2$ | $2$ | $45$ | $21$ | $1^{20}\cdot2^{2}$ |
| 56.1344.45-56.ge.1.2 | $56$ | $2$ | $2$ | $45$ | $13$ | $1^{12}\cdot2^{6}$ |
| 56.1344.45-56.ge.1.13 | $56$ | $2$ | $2$ | $45$ | $13$ | $1^{12}\cdot2^{6}$ |
| 56.1344.45-56.gf.1.1 | $56$ | $2$ | $2$ | $45$ | $20$ | $1^{12}\cdot2^{6}$ |
| 56.1344.45-56.gf.1.15 | $56$ | $2$ | $2$ | $45$ | $20$ | $1^{12}\cdot2^{6}$ |