Properties

Label 80.240.8-40.bj.1.8
Level $80$
Index $240$
Genus $8$
Cusps $6$
$\Q$-cusps $4$

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Invariants

Level: $80$ $\SL_2$-level: $80$ Newform level: $400$
Index: $240$ $\PSL_2$-index:$120$
Genus: $8 = 1 + \frac{ 120 }{12} - \frac{ 0 }{4} - \frac{ 0 }{3} - \frac{ 6 }{2}$
Cusps: $6$ (of which $4$ are rational) Cusp widths $10^{4}\cdot40^{2}$ Cusp orbits $1^{4}\cdot2$
Elliptic points: $0$ of order $2$ and $0$ of order $3$
Analytic rank: not computed
$\Q$-gonality: $3 \le \gamma \le 8$
$\overline{\Q}$-gonality: $3 \le \gamma \le 8$
Rational cusps: $4$
Rational CM points: none

Other labels

Cummins and Pauli (CP) label: 40A8

Level structure

$\GL_2(\Z/80\Z)$-generators: $\begin{bmatrix}9&6\\32&21\end{bmatrix}$, $\begin{bmatrix}33&23\\8&7\end{bmatrix}$, $\begin{bmatrix}37&49\\0&11\end{bmatrix}$, $\begin{bmatrix}55&74\\24&3\end{bmatrix}$, $\begin{bmatrix}59&57\\40&1\end{bmatrix}$, $\begin{bmatrix}79&20\\16&67\end{bmatrix}$
Contains $-I$: no $\quad$ (see 40.120.8.bj.1 for the level structure with $-I$)
Cyclic 80-isogeny field degree: $12$
Cyclic 80-torsion field degree: $192$
Full 80-torsion field degree: $49152$

Models

Canonical model in $\mathbb{P}^{ 7 }$ defined by 15 equations

$ 0 $ $=$ $ x^{2} - t^{2} - 2 u v + v^{2} $
$=$ $2 x y - x r + z v - t v - t r$
$=$ $x y - y t + 2 z v + w v$
$=$ $x u - x r - z u + z v - 2 t u$
$=$$\cdots$
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Singular plane model Singular plane model

$ 0 $ $=$ $ - 16 x^{10} - 8 x^{8} z^{2} - 16 x^{6} y^{4} + 32 x^{6} y^{2} z^{2} - 9 x^{6} z^{4} - 13 x^{4} y^{4} z^{2} + \cdots + 2 y^{2} z^{8} $
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Rational points

This modular curve has 4 rational cusps but no known non-cuspidal rational points. The following are the coordinates of the rational cusps on this modular curve.

Canonical model
$(0:0:0:0:-1:0:-1:1)$, $(0:0:0:0:0:1:0:0)$, $(0:0:0:0:0:1/2:1:1)$, $(0:0:0:0:1:0:-1:1)$

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 20.60.4.h.1 :

$\displaystyle X$ $=$ $\displaystyle x$
$\displaystyle Y$ $=$ $\displaystyle z$
$\displaystyle Z$ $=$ $\displaystyle u-v$
$\displaystyle W$ $=$ $\displaystyle v-r$

Equation of the image curve:

$0$ $=$ $ 7X^{2}+Y^{2}+2ZW+W^{2} $
$=$ $ X^{3}-XY^{2}+XZ^{2}+YZ^{2}+YZW $

Map of degree 1 from the canonical model of this modular curve to the plane model of the modular curve 40.120.8.bj.1 :

$\displaystyle X$ $=$ $\displaystyle x$
$\displaystyle Y$ $=$ $\displaystyle \frac{1}{2}y+\frac{1}{2}w$
$\displaystyle Z$ $=$ $\displaystyle z$

Equation of the image curve:

$0$ $=$ $ -16X^{10}-8X^{8}Z^{2}-16X^{6}Y^{4}+32X^{6}Y^{2}Z^{2}-9X^{6}Z^{4}-13X^{4}Y^{4}Z^{2}+26X^{4}Y^{2}Z^{4}-2X^{4}Z^{6}-4X^{2}Y^{8}+16X^{2}Y^{6}Z^{2}-26X^{2}Y^{4}Z^{4}+20X^{2}Y^{2}Z^{6}-X^{2}Z^{8}-Y^{4}Z^{6}+2Y^{2}Z^{8} $

Modular covers

The following modular covers realize this modular curve as a fiber product over $X(1)$.

Factor curve Level Index Degree Genus Rank
$X_{S_4}(5)$ $5$ $48$ $24$ $0$ $0$
16.48.0-8.q.1.2 $16$ $5$ $5$ $0$ $0$

This modular curve minimally covers the modular curves listed below.

Covered curve Level Index Degree Genus Rank
16.48.0-8.q.1.2 $16$ $5$ $5$ $0$ $0$
80.120.4-40.bl.1.5 $80$ $2$ $2$ $4$ $?$
80.120.4-40.bl.1.12 $80$ $2$ $2$ $4$ $?$

This modular curve is minimally covered by the modular curves in the database listed below.

Covering curve Level Index Degree Genus
80.480.16-80.u.1.2 $80$ $2$ $2$ $16$
80.480.16-80.u.1.7 $80$ $2$ $2$ $16$
80.480.16-80.v.1.3 $80$ $2$ $2$ $16$
80.480.16-80.v.1.6 $80$ $2$ $2$ $16$
80.480.16-80.w.1.5 $80$ $2$ $2$ $16$
80.480.16-80.w.1.11 $80$ $2$ $2$ $16$
80.480.16-80.x.1.3 $80$ $2$ $2$ $16$
80.480.16-80.x.1.13 $80$ $2$ $2$ $16$
80.480.16-40.bs.1.4 $80$ $2$ $2$ $16$
80.480.16-40.bs.1.6 $80$ $2$ $2$ $16$
80.480.16-40.bs.1.9 $80$ $2$ $2$ $16$
80.480.16-40.bs.2.4 $80$ $2$ $2$ $16$
80.480.16-40.bs.2.7 $80$ $2$ $2$ $16$
80.480.16-40.bs.2.9 $80$ $2$ $2$ $16$
80.480.16-40.bt.1.4 $80$ $2$ $2$ $16$
80.480.16-40.bt.1.5 $80$ $2$ $2$ $16$
80.480.16-40.bt.1.10 $80$ $2$ $2$ $16$
80.480.16-40.bt.2.2 $80$ $2$ $2$ $16$
80.480.16-40.bt.2.7 $80$ $2$ $2$ $16$
80.480.16-40.bt.2.11 $80$ $2$ $2$ $16$
80.480.17-80.m.1.5 $80$ $2$ $2$ $17$
80.480.17-80.m.1.10 $80$ $2$ $2$ $17$
80.480.17-80.m.1.17 $80$ $2$ $2$ $17$
80.480.17-80.n.1.3 $80$ $2$ $2$ $17$
80.480.17-80.n.1.10 $80$ $2$ $2$ $17$
80.480.17-80.n.1.17 $80$ $2$ $2$ $17$
80.480.17-80.o.1.3 $80$ $2$ $2$ $17$
80.480.17-80.o.1.6 $80$ $2$ $2$ $17$
80.480.17-80.o.1.17 $80$ $2$ $2$ $17$
80.480.17-80.p.1.3 $80$ $2$ $2$ $17$
80.480.17-80.p.1.6 $80$ $2$ $2$ $17$
80.480.17-80.p.1.17 $80$ $2$ $2$ $17$
80.480.17-40.fe.1.2 $80$ $2$ $2$ $17$
80.480.17-40.ff.1.8 $80$ $2$ $2$ $17$
80.480.17-40.fg.1.3 $80$ $2$ $2$ $17$
80.480.17-40.fh.1.2 $80$ $2$ $2$ $17$
80.480.18-80.t.1.1 $80$ $2$ $2$ $18$
80.480.18-80.t.1.8 $80$ $2$ $2$ $18$
80.480.18-80.u.1.2 $80$ $2$ $2$ $18$
80.480.18-80.u.1.8 $80$ $2$ $2$ $18$
240.480.16-240.u.1.4 $240$ $2$ $2$ $16$
240.480.16-240.u.1.23 $240$ $2$ $2$ $16$
240.480.16-240.v.1.15 $240$ $2$ $2$ $16$
240.480.16-240.v.1.28 $240$ $2$ $2$ $16$
240.480.16-240.w.1.7 $240$ $2$ $2$ $16$
240.480.16-240.w.1.20 $240$ $2$ $2$ $16$
240.480.16-240.x.1.12 $240$ $2$ $2$ $16$
240.480.16-240.x.1.31 $240$ $2$ $2$ $16$
240.480.16-120.eg.1.8 $240$ $2$ $2$ $16$
240.480.16-120.eg.1.11 $240$ $2$ $2$ $16$
240.480.16-120.eg.1.22 $240$ $2$ $2$ $16$
240.480.16-120.eg.2.6 $240$ $2$ $2$ $16$
240.480.16-120.eg.2.9 $240$ $2$ $2$ $16$
240.480.16-120.eg.2.24 $240$ $2$ $2$ $16$
240.480.16-120.eh.1.8 $240$ $2$ $2$ $16$
240.480.16-120.eh.1.9 $240$ $2$ $2$ $16$
240.480.16-120.eh.1.13 $240$ $2$ $2$ $16$
240.480.16-120.eh.2.7 $240$ $2$ $2$ $16$
240.480.16-120.eh.2.10 $240$ $2$ $2$ $16$
240.480.16-120.eh.2.14 $240$ $2$ $2$ $16$
240.480.17-240.m.1.12 $240$ $2$ $2$ $17$
240.480.17-240.m.1.29 $240$ $2$ $2$ $17$
240.480.17-240.m.1.37 $240$ $2$ $2$ $17$
240.480.17-240.n.1.15 $240$ $2$ $2$ $17$
240.480.17-240.n.1.30 $240$ $2$ $2$ $17$
240.480.17-240.n.1.33 $240$ $2$ $2$ $17$
240.480.17-240.o.1.15 $240$ $2$ $2$ $17$
240.480.17-240.o.1.30 $240$ $2$ $2$ $17$
240.480.17-240.o.1.33 $240$ $2$ $2$ $17$
240.480.17-240.p.1.8 $240$ $2$ $2$ $17$
240.480.17-240.p.1.27 $240$ $2$ $2$ $17$
240.480.17-240.p.1.41 $240$ $2$ $2$ $17$
240.480.17-120.nm.1.1 $240$ $2$ $2$ $17$
240.480.17-120.nn.1.3 $240$ $2$ $2$ $17$
240.480.17-120.no.1.5 $240$ $2$ $2$ $17$
240.480.17-120.np.1.1 $240$ $2$ $2$ $17$
240.480.18-240.q.1.13 $240$ $2$ $2$ $18$
240.480.18-240.q.1.26 $240$ $2$ $2$ $18$
240.480.18-240.r.1.16 $240$ $2$ $2$ $18$
240.480.18-240.r.1.26 $240$ $2$ $2$ $18$