Properties

Label 126.216.6-18.a.1.1
Level $126$
Index $216$
Genus $6$
Cusps $8$
$\Q$-cusps $4$

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Invariants

Level: $126$ $\SL_2$-level: $18$ Newform level: $162$
Index: $216$ $\PSL_2$-index:$108$
Genus: $6 = 1 + \frac{ 108 }{12} - \frac{ 0 }{4} - \frac{ 0 }{3} - \frac{ 8 }{2}$
Cusps: $8$ (of which $4$ are rational) Cusp widths $9^{4}\cdot18^{4}$ Cusp orbits $1^{4}\cdot2^{2}$
Elliptic points: $0$ of order $2$ and $0$ of order $3$
Analytic rank: not computed
$\Q$-gonality: $3 \le \gamma \le 6$
$\overline{\Q}$-gonality: $3 \le \gamma \le 6$
Rational cusps: $4$
Rational CM points: none

Other labels

Cummins and Pauli (CP) label: 18A6

Level structure

$\GL_2(\Z/126\Z)$-generators: $\begin{bmatrix}9&68\\50&51\end{bmatrix}$, $\begin{bmatrix}113&30\\66&107\end{bmatrix}$, $\begin{bmatrix}123&43\\94&99\end{bmatrix}$
Contains $-I$: no $\quad$ (see 18.108.6.a.1 for the level structure with $-I$)
Cyclic 126-isogeny field degree: $24$
Cyclic 126-torsion field degree: $864$
Full 126-torsion field degree: $217728$

Models

Canonical model in $\mathbb{P}^{ 5 }$ defined by 9 equations

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

$ 0 $ $=$ $ - 2 x^{3} y^{3} z + x^{3} y^{2} z^{2} + 4 y^{7} - 2 y^{6} z + 3 y^{5} z^{2} + 5 y^{4} z^{3} - y^{3} z^{4} + \cdots + z^{7} $
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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
$(0:-1:0:1:0:0)$, $(1/2:0:0:0:0:1)$, $(0:0:1:0:0:0)$, $(-1/2:0:0:0:1:0)$

Maps to other modular curves

$j$-invariant map of degree 108 from the canonical model of this modular curve to the modular curve $X(1)$ :

$\displaystyle j$ $=$ $\displaystyle -\frac{824526xt^{2}u^{9}-467638xtu^{10}+986094xu^{11}+81yw^{11}-391986yw^{8}u^{3}-88823yw^{5}u^{6}-721738yw^{2}u^{9}-13824z^{9}u^{3}-145152z^{6}u^{6}-539136z^{3}u^{9}-81zw^{11}+88722zw^{8}u^{3}+65021zw^{5}u^{6}+76922zw^{2}u^{9}+81w^{12}+14067w^{9}t^{3}+75789w^{9}t^{2}u+228231w^{9}tu^{2}+62505w^{9}u^{3}+790911w^{6}t^{3}u^{3}+314622w^{6}t^{2}u^{4}+662079w^{6}tu^{5}+71622w^{6}u^{6}+221998w^{3}t^{3}u^{6}+26532w^{3}t^{2}u^{7}+746999w^{3}tu^{8}+69742w^{3}u^{9}-27t^{12}-108t^{11}u-108t^{10}u^{2}-729t^{9}u^{3}-5085t^{8}u^{4}-110202t^{7}u^{5}-398428t^{6}u^{6}-858445t^{5}u^{7}-1053406t^{4}u^{8}-501418t^{3}u^{9}-536950t^{2}u^{10}-236872tu^{11}-493074u^{12}}{u^{3}(48xt^{2}u^{6}+48xtu^{7}+105yw^{5}u^{3}-24yw^{2}u^{6}+9zw^{5}u^{3}-24zw^{2}u^{6}-57w^{6}tu^{2}-126w^{3}t^{3}u^{3}+24w^{3}t^{2}u^{4}-48w^{3}tu^{5}+48w^{3}u^{6}+t^{9}+3t^{8}u-23t^{6}u^{3}-24t^{5}u^{4}-45t^{4}u^{5}-47t^{3}u^{6}-48t^{2}u^{7}-24tu^{8})}$

Map of degree 1 from the canonical model of this modular curve to the plane model of the modular curve 18.108.6.a.1 :

$\displaystyle X$ $=$ $\displaystyle x$
$\displaystyle Y$ $=$ $\displaystyle \frac{1}{3}y$
$\displaystyle Z$ $=$ $\displaystyle \frac{1}{3}w$

Equation of the image curve:

$0$ $=$ $ -2X^{3}Y^{3}Z+X^{3}Y^{2}Z^{2}+4Y^{7}-2Y^{6}Z+3Y^{5}Z^{2}+5Y^{4}Z^{3}-Y^{3}Z^{4}+3Y^{2}Z^{5}+YZ^{6}+Z^{7} $

Modular covers

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

Factor curve Level Index Degree Genus Rank
$X_0(2)$ $2$ $72$ $36$ $0$ $0$
63.72.2-9.a.1.1 $63$ $3$ $3$ $2$ $0$

This modular curve minimally covers the modular curves listed below.

Covered curve Level Index Degree Genus Rank
42.72.0-6.a.1.1 $42$ $3$ $3$ $0$ $0$
63.72.2-9.a.1.1 $63$ $3$ $3$ $2$ $0$

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

Covering curve Level Index Degree Genus
126.432.13-18.a.1.1 $126$ $2$ $2$ $13$
126.432.13-18.p.1.1 $126$ $2$ $2$ $13$
126.432.13-126.bh.1.2 $126$ $2$ $2$ $13$
126.432.13-126.bx.1.2 $126$ $2$ $2$ $13$
252.432.13-36.b.1.2 $252$ $2$ $2$ $13$
252.432.13-36.d.1.1 $252$ $2$ $2$ $13$
252.432.13-36.f.1.1 $252$ $2$ $2$ $13$
252.432.13-36.z.1.1 $252$ $2$ $2$ $13$
252.432.13-36.ba.1.1 $252$ $2$ $2$ $13$
252.432.13-36.bd.1.2 $252$ $2$ $2$ $13$
252.432.13-252.bn.1.5 $252$ $2$ $2$ $13$
252.432.13-252.bq.1.2 $252$ $2$ $2$ $13$
252.432.13-252.br.1.4 $252$ $2$ $2$ $13$
252.432.13-252.cn.1.3 $252$ $2$ $2$ $13$
252.432.13-252.co.1.2 $252$ $2$ $2$ $13$
252.432.13-252.cr.1.5 $252$ $2$ $2$ $13$
252.432.15-36.cq.1.1 $252$ $2$ $2$ $15$
252.432.15-36.cr.1.1 $252$ $2$ $2$ $15$
252.432.15-36.do.1.1 $252$ $2$ $2$ $15$
252.432.15-36.dq.1.1 $252$ $2$ $2$ $15$
252.432.15-252.qq.1.2 $252$ $2$ $2$ $15$
252.432.15-252.qr.1.2 $252$ $2$ $2$ $15$
252.432.15-252.su.1.3 $252$ $2$ $2$ $15$
252.432.15-252.sv.1.4 $252$ $2$ $2$ $15$