Properties

Label 120.240.8-40.a.1.2
Level $120$
Index $240$
Genus $8$
Cusps $6$
$\Q$-cusps $0$

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Invariants

Level: $120$ $\SL_2$-level: $20$ Newform level: $1600$
Index: $240$ $\PSL_2$-index:$120$
Genus: $8 = 1 + \frac{ 120 }{12} - \frac{ 0 }{4} - \frac{ 0 }{3} - \frac{ 6 }{2}$
Cusps: $6$ (none of which are rational) Cusp widths $20^{6}$ Cusp orbits $2^{3}$
Elliptic points: $0$ of order $2$ and $0$ of order $3$
Analytic rank: not computed
$\Q$-gonality: $3 \le \gamma \le 14$
$\overline{\Q}$-gonality: $3 \le \gamma \le 8$
Rational cusps: $0$
Rational CM points: none

Other labels

Cummins and Pauli (CP) label: 20A8

Level structure

$\GL_2(\Z/120\Z)$-generators: $\begin{bmatrix}1&66\\102&55\end{bmatrix}$, $\begin{bmatrix}49&84\\28&55\end{bmatrix}$, $\begin{bmatrix}59&56\\40&53\end{bmatrix}$, $\begin{bmatrix}87&38\\2&25\end{bmatrix}$, $\begin{bmatrix}101&36\\72&5\end{bmatrix}$
Contains $-I$: no $\quad$ (see 40.120.8.a.1 for the level structure with $-I$)
Cyclic 120-isogeny field degree: $96$
Cyclic 120-torsion field degree: $3072$
Full 120-torsion field degree: $147456$

Models

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

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

$ 0 $ $=$ $ 32 x^{10} - 16 x^{8} y^{2} + 32 x^{8} z^{2} + 2 x^{6} y^{4} - 44 x^{6} y^{2} z^{2} + 8 x^{6} z^{4} + \cdots + 8 y^{2} z^{8} $
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Rational points

This modular curve has real points and $\Q_p$ points for $p$ not dividing the level, but no known rational points.

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.a.1 :

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

Equation of the image curve:

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

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

$\displaystyle X$ $=$ $\displaystyle x$
$\displaystyle Y$ $=$ $\displaystyle z$
$\displaystyle Z$ $=$ $\displaystyle \frac{1}{2}t$

Equation of the image curve:

$0$ $=$ $ 32X^{10}-16X^{8}Y^{2}+32X^{8}Z^{2}+2X^{6}Y^{4}-44X^{6}Y^{2}Z^{2}+8X^{6}Z^{4}-X^{4}Y^{4}Z^{2}+2X^{4}Y^{2}Z^{4}+6X^{2}Y^{6}Z^{2}+8X^{2}Y^{4}Z^{4}+24X^{2}Y^{2}Z^{6}-Y^{8}Z^{2}+6Y^{6}Z^{4}-12Y^{4}Z^{6}+8Y^{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
$X_{S_4}(5)$ $5$ $48$ $24$ $0$ $0$
24.48.0-8.a.1.3 $24$ $5$ $5$ $0$ $0$

This modular curve minimally covers the modular curves listed below.

Covered curve Level Index Degree Genus Rank
24.48.0-8.a.1.3 $24$ $5$ $5$ $0$ $0$
60.120.4-20.a.1.4 $60$ $2$ $2$ $4$ $1$
120.120.4-20.a.1.2 $120$ $2$ $2$ $4$ $?$
120.120.4-40.a.1.1 $120$ $2$ $2$ $4$ $?$
120.120.4-40.a.1.2 $120$ $2$ $2$ $4$ $?$
120.120.4-40.a.1.6 $120$ $2$ $2$ $4$ $?$

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

Covering curve Level Index Degree Genus
120.480.17-40.e.1.1 $120$ $2$ $2$ $17$
120.480.17-120.e.1.7 $120$ $2$ $2$ $17$
120.480.17-40.f.1.1 $120$ $2$ $2$ $17$
120.480.17-120.f.1.8 $120$ $2$ $2$ $17$
120.480.17-40.g.1.3 $120$ $2$ $2$ $17$
120.480.17-120.g.1.7 $120$ $2$ $2$ $17$
120.480.17-40.h.1.3 $120$ $2$ $2$ $17$
120.480.17-120.h.1.8 $120$ $2$ $2$ $17$
240.480.16-80.a.1.2 $240$ $2$ $2$ $16$
240.480.16-240.a.1.7 $240$ $2$ $2$ $16$
240.480.16-80.b.1.2 $240$ $2$ $2$ $16$
240.480.16-240.b.1.7 $240$ $2$ $2$ $16$
240.480.16-80.c.1.2 $240$ $2$ $2$ $16$
240.480.16-240.c.1.7 $240$ $2$ $2$ $16$
240.480.16-80.d.1.2 $240$ $2$ $2$ $16$
240.480.16-240.d.1.7 $240$ $2$ $2$ $16$
240.480.18-80.a.1.8 $240$ $2$ $2$ $18$
240.480.18-240.a.1.7 $240$ $2$ $2$ $18$
240.480.18-80.b.1.8 $240$ $2$ $2$ $18$
240.480.18-240.b.1.6 $240$ $2$ $2$ $18$
240.480.18-80.c.1.8 $240$ $2$ $2$ $18$
240.480.18-240.c.1.6 $240$ $2$ $2$ $18$
240.480.18-80.d.1.8 $240$ $2$ $2$ $18$
240.480.18-240.d.1.4 $240$ $2$ $2$ $18$