Properties

Label 80.240.8-40.dd.2.1
Level $80$
Index $240$
Genus $8$
Cusps $6$
$\Q$-cusps $4$

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Invariants

Level: $80$ $\SL_2$-level: $80$ Newform level: $200$
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 $5^{2}\cdot10\cdot20\cdot40^{2}$ 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: 40C8

Level structure

$\GL_2(\Z/80\Z)$-generators: $\begin{bmatrix}20&79\\77&30\end{bmatrix}$, $\begin{bmatrix}21&48\\70&23\end{bmatrix}$, $\begin{bmatrix}29&6\\20&63\end{bmatrix}$, $\begin{bmatrix}30&63\\7&78\end{bmatrix}$, $\begin{bmatrix}48&57\\57&72\end{bmatrix}$
Contains $-I$: no $\quad$ (see 40.120.8.dd.2 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 t + x v - x r - z u - w t - w u - w v - w r $
$=$ $x^{2} - x w + y z + 2 w^{2}$
$=$ $x t - x v + x r - y t - z t - z v - w u$
$=$ $2 x^{2} - x z + 2 x w + y w - z w + t^{2} - u v - v^{2}$
$=$$\cdots$
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Singular plane model Singular plane model

$ 0 $ $=$ $ 512 x^{14} - 52 x^{12} y^{2} - 880 x^{12} y z - 1808 x^{12} z^{2} + 4 x^{10} y^{4} + 60 x^{10} y^{3} z + \cdots - 8 y z^{13} $
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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
$(0:0:0:0:-1/2:0:1/2:1)$, $(1/3:2/3:-1/3:1/3:-1/3:0:1:0)$, $(-1/3:-2/3:1/3:-1/3:-1/3:0:1:0)$, $(0:0:0:0:1:0:1:0)$

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 40.60.4.bl.1 :

$\displaystyle X$ $=$ $\displaystyle x$
$\displaystyle Y$ $=$ $\displaystyle -y$
$\displaystyle Z$ $=$ $\displaystyle w$
$\displaystyle W$ $=$ $\displaystyle -z$

Equation of the image curve:

$0$ $=$ $ X^{2}-XZ+2Z^{2}+YW $
$=$ $ 2X^{2}Z-Y^{2}Z-2Z^{3}+XYW-YZW+2XW^{2}+2ZW^{2} $

Map of degree 1 from the canonical model of this modular curve to the plane model of the modular curve 40.120.8.dd.2 :

$\displaystyle X$ $=$ $\displaystyle w$
$\displaystyle Y$ $=$ $\displaystyle \frac{1}{2}r$
$\displaystyle Z$ $=$ $\displaystyle t$

Equation of the image curve:

$0$ $=$ $ 512X^{14}-52X^{12}Y^{2}+4X^{10}Y^{4}-880X^{12}YZ+60X^{10}Y^{3}Z-1808X^{12}Z^{2}+564X^{10}Y^{2}Z^{2}+28X^{8}Y^{4}Z^{2}+3608X^{10}YZ^{3}+280X^{8}Y^{3}Z^{3}-12X^{6}Y^{5}Z^{3}+1632X^{10}Z^{4}-2369X^{8}Y^{2}Z^{4}-141X^{6}Y^{4}Z^{4}-18X^{4}Y^{6}Z^{4}-2124X^{8}YZ^{5}+1353X^{6}Y^{3}Z^{5}-192X^{4}Y^{5}Z^{5}+12X^{2}Y^{7}Z^{5}-1044X^{8}Z^{6}+2524X^{6}Y^{2}Z^{6}-1215X^{4}Y^{4}Z^{6}+131X^{2}Y^{6}Z^{6}-2Y^{8}Z^{6}+2538X^{6}YZ^{7}-2588X^{4}Y^{3}Z^{7}+581X^{2}Y^{5}Z^{7}-22Y^{7}Z^{7}+916X^{6}Z^{8}-2849X^{4}Y^{2}Z^{8}+1231X^{2}Y^{4}Z^{8}-94Y^{6}Z^{8}-1422X^{4}YZ^{9}+1395X^{2}Y^{3}Z^{9}-202Y^{5}Z^{9}-224X^{4}Z^{10}+818X^{2}Y^{2}Z^{10}-240Y^{4}Z^{10}+216X^{2}YZ^{11}-160Y^{3}Z^{11}+16X^{2}Z^{12}-56Y^{2}Z^{12}-8YZ^{13} $

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.bb.2.8 $16$ $5$ $5$ $0$ $0$

This modular curve minimally covers the modular curves listed below.

Covered curve Level Index Degree Genus Rank
16.48.0-8.bb.2.8 $16$ $5$ $5$ $0$ $0$
80.120.4-40.bl.1.1 $80$ $2$ $2$ $4$ $?$
80.120.4-40.bl.1.5 $80$ $2$ $2$ $4$ $?$

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

Covering curve Level Index Degree Genus
80.480.16-40.bp.2.11 $80$ $2$ $2$ $16$
80.480.16-40.br.1.8 $80$ $2$ $2$ $16$
80.480.16-40.bt.2.11 $80$ $2$ $2$ $16$
80.480.16-40.bx.1.7 $80$ $2$ $2$ $16$
80.480.16-40.bz.2.6 $80$ $2$ $2$ $16$
80.480.16-40.cb.1.8 $80$ $2$ $2$ $16$
80.480.16-40.cd.2.6 $80$ $2$ $2$ $16$
80.480.16-40.cf.2.6 $80$ $2$ $2$ $16$
80.480.16-80.ch.2.1 $80$ $2$ $2$ $16$
80.480.16-80.cj.2.1 $80$ $2$ $2$ $16$
80.480.16-80.cp.2.1 $80$ $2$ $2$ $16$
80.480.16-80.cr.2.1 $80$ $2$ $2$ $16$
80.480.16-80.cv.2.9 $80$ $2$ $2$ $16$
80.480.16-80.db.2.1 $80$ $2$ $2$ $16$
80.480.16-80.dd.2.1 $80$ $2$ $2$ $16$
80.480.16-80.dj.2.1 $80$ $2$ $2$ $16$
80.480.17-80.bx.2.1 $80$ $2$ $2$ $17$
80.480.17-80.cd.2.1 $80$ $2$ $2$ $17$
80.480.17-80.cf.2.9 $80$ $2$ $2$ $17$
80.480.17-80.cl.2.1 $80$ $2$ $2$ $17$
80.480.17-80.cv.2.1 $80$ $2$ $2$ $17$
80.480.17-80.cx.2.1 $80$ $2$ $2$ $17$
80.480.17-80.dd.2.1 $80$ $2$ $2$ $17$
80.480.17-80.df.2.1 $80$ $2$ $2$ $17$
240.480.16-240.dr.2.1 $240$ $2$ $2$ $16$
240.480.16-240.dt.2.1 $240$ $2$ $2$ $16$
240.480.16-240.eh.2.1 $240$ $2$ $2$ $16$
240.480.16-240.ej.2.1 $240$ $2$ $2$ $16$
240.480.16-120.er.2.15 $240$ $2$ $2$ $16$
240.480.16-120.ev.1.11 $240$ $2$ $2$ $16$
240.480.16-120.ez.2.16 $240$ $2$ $2$ $16$
240.480.16-120.fd.2.14 $240$ $2$ $2$ $16$
240.480.16-240.fj.2.2 $240$ $2$ $2$ $16$
240.480.16-240.ft.2.2 $240$ $2$ $2$ $16$
240.480.16-240.fz.2.2 $240$ $2$ $2$ $16$
240.480.16-120.gb.1.13 $240$ $2$ $2$ $16$
240.480.16-120.gf.1.14 $240$ $2$ $2$ $16$
240.480.16-120.gj.2.5 $240$ $2$ $2$ $16$
240.480.16-240.gj.2.2 $240$ $2$ $2$ $16$
240.480.16-120.gn.2.6 $240$ $2$ $2$ $16$
240.480.17-240.en.2.2 $240$ $2$ $2$ $17$
240.480.17-240.ex.2.2 $240$ $2$ $2$ $17$
240.480.17-240.fd.2.2 $240$ $2$ $2$ $17$
240.480.17-240.fn.1.2 $240$ $2$ $2$ $17$
240.480.17-240.in.1.2 $240$ $2$ $2$ $17$
240.480.17-240.ip.1.2 $240$ $2$ $2$ $17$
240.480.17-240.jd.2.2 $240$ $2$ $2$ $17$
240.480.17-240.jf.1.2 $240$ $2$ $2$ $17$