Properties

Label 72.144.4-36.m.1.2
Level $72$
Index $144$
Genus $4$
Cusps $6$
$\Q$-cusps $2$

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Invariants

Level: $72$ $\SL_2$-level: $36$ Newform level: $432$
Index: $144$ $\PSL_2$-index:$72$
Genus: $4 = 1 + \frac{ 72 }{12} - \frac{ 0 }{4} - \frac{ 0 }{3} - \frac{ 6 }{2}$
Cusps: $6$ (of which $2$ are rational) Cusp widths $6^{3}\cdot18^{3}$ Cusp orbits $1^{2}\cdot2^{2}$
Elliptic points: $0$ of order $2$ and $0$ of order $3$
Analytic rank: not computed
$\Q$-gonality: $3 \le \gamma \le 4$
$\overline{\Q}$-gonality: $3 \le \gamma \le 4$
Rational cusps: $2$
Rational CM points: none

Other labels

Cummins and Pauli (CP) label: 18C4

Level structure

$\GL_2(\Z/72\Z)$-generators: $\begin{bmatrix}7&48\\58&65\end{bmatrix}$, $\begin{bmatrix}14&13\\3&4\end{bmatrix}$, $\begin{bmatrix}35&30\\44&1\end{bmatrix}$, $\begin{bmatrix}62&13\\27&22\end{bmatrix}$
Contains $-I$: no $\quad$ (see 36.72.4.m.1 for the level structure with $-I$)
Cyclic 72-isogeny field degree: $12$
Cyclic 72-torsion field degree: $288$
Full 72-torsion field degree: $41472$

Models

Canonical model in $\mathbb{P}^{ 3 }$

$ 0 $ $=$ $ 3 x z - y w $
$=$ $3 x^{3} - x y^{2} + 3 z^{3} - 9 z w^{2}$
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Singular plane model Singular plane model

$ 0 $ $=$ $ x^{6} - 3 x^{4} y^{2} - 3 x^{2} y z^{3} + y^{3} z^{3} $
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Rational points

This modular curve has 2 rational cusps but no known non-cuspidal rational points. The following are the coordinates of the rational cusps on this modular curve.

Canonical model
$(0:0:0:1)$, $(0:1:0:0)$

Maps to other modular curves

$j$-invariant map of degree 72 from the canonical model of this modular curve to the modular curve $X(1)$ :

$\displaystyle j$ $=$ $\displaystyle \frac{12285x^{2}y^{10}+257985x^{2}y^{7}w^{3}+633015x^{2}y^{4}w^{6}-91125x^{2}yw^{9}+y^{12}-12285y^{9}z^{2}w+32796y^{9}w^{3}-157545y^{6}z^{2}w^{4}+456030y^{6}w^{6}-30375y^{3}z^{2}w^{7}+209196y^{3}w^{9}+995085z^{2}w^{10}+729w^{12}}{w^{4}y(9x^{2}y^{3}w^{2}+27x^{2}w^{5}+3y^{5}z^{2}-4y^{5}w^{2}+9y^{2}z^{2}w^{3}-28y^{2}w^{5})}$

Map of degree 1 from the canonical model of this modular curve to the plane model of the modular curve 36.72.4.m.1 :

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

Equation of the image curve:

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

Modular covers

This modular curve minimally covers the modular curves listed below.

Covered curve Level Index Degree Genus Rank
24.48.0-12.h.1.6 $24$ $3$ $3$ $0$ $0$
72.72.2-18.d.1.1 $72$ $2$ $2$ $2$ $?$
72.72.2-18.d.1.4 $72$ $2$ $2$ $2$ $?$

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

Covering curve Level Index Degree Genus
72.288.9-36.t.1.1 $72$ $2$ $2$ $9$
72.288.9-36.x.1.3 $72$ $2$ $2$ $9$
72.288.9-36.cg.1.3 $72$ $2$ $2$ $9$
72.288.9-36.ck.1.4 $72$ $2$ $2$ $9$
72.432.10-36.s.1.2 $72$ $3$ $3$ $10$
72.432.10-36.s.2.2 $72$ $3$ $3$ $10$
72.432.10-36.ba.1.8 $72$ $3$ $3$ $10$
72.432.10-36.bc.1.3 $72$ $3$ $3$ $10$
72.288.9-72.ck.1.8 $72$ $2$ $2$ $9$
72.288.9-72.cw.1.4 $72$ $2$ $2$ $9$
72.288.9-72.fb.1.2 $72$ $2$ $2$ $9$
72.288.9-72.fn.1.1 $72$ $2$ $2$ $9$
216.432.16-108.s.1.2 $216$ $3$ $3$ $16$
216.432.16-108.t.1.2 $216$ $3$ $3$ $16$
216.432.16-108.u.1.2 $216$ $3$ $3$ $16$