Invariants
Level: | $84$ | $\SL_2$-level: | $12$ | Newform level: | $144$ | ||
Index: | $72$ | $\PSL_2$-index: | $36$ | ||||
Genus: | $2 = 1 + \frac{ 36 }{12} - \frac{ 0 }{4} - \frac{ 0 }{3} - \frac{ 4 }{2}$ | ||||||
Cusps: | $4$ (of which $2$ are rational) | Cusp widths | $6^{2}\cdot12^{2}$ | Cusp orbits | $1^{2}\cdot2$ | ||
Elliptic points: | $0$ of order $2$ and $0$ of order $3$ | ||||||
Analytic rank: | not computed | ||||||
$\Q$-gonality: | $2$ | ||||||
$\overline{\Q}$-gonality: | $2$ | ||||||
Rational cusps: | $2$ | ||||||
Rational CM points: | none |
Other labels
Cummins and Pauli (CP) label: | 12B2 |
Level structure
$\GL_2(\Z/84\Z)$-generators: | $\begin{bmatrix}11&80\\2&57\end{bmatrix}$, $\begin{bmatrix}33&62\\8&61\end{bmatrix}$, $\begin{bmatrix}53&54\\28&73\end{bmatrix}$, $\begin{bmatrix}63&22\\76&23\end{bmatrix}$, $\begin{bmatrix}63&32\\8&55\end{bmatrix}$ |
Contains $-I$: | no $\quad$ (see 12.36.2.a.1 for the level structure with $-I$) |
Cyclic 84-isogeny field degree: | $64$ |
Cyclic 84-torsion field degree: | $1536$ |
Full 84-torsion field degree: | $129024$ |
Models
Embedded model Embedded model in $\mathbb{P}^{3}$
$ 0 $ | $=$ | $ x^{2} w + y^{2} z + z^{2} w $ |
$=$ | $x y w - 4 w^{3}$ | |
$=$ | $x y z - 4 z w^{2}$ | |
$=$ | $x y^{2} - 4 y w^{2}$ | |
$=$ | $\cdots$ |
Singular plane model Singular plane model
$ 0 $ | $=$ | $ 2 x^{4} y + x^{2} y^{2} z + z^{5} $ |
Weierstrass model Weierstrass model
$ y^{2} $ | $=$ | $ x^{6} - 1 $ |
Rational points
This modular curve has 2 rational cusps but no known non-cuspidal rational points. The following are the known rational points on this modular curve (one row per $j$-invariant).
Elliptic curve | CM | $j$-invariant | $j$-height | Plane model | Weierstrass model | Embedded model | |
---|---|---|---|---|---|---|---|
no | $\infty$ | $0.000$ | |||||
32.a3 | $-4$ | $1728$ | $= 2^{6} \cdot 3^{3}$ | $7.455$ | $(-1:-1:1)$, $(1:-1:1)$ | $(-1:0:1)$, $(1:0:1)$ | $(-2:-2:-2:1)$, $(2:2:-2:1)$ |
Maps to other modular curves
$j$-invariant map of degree 36 from the embedded model of this modular curve to the modular curve $X(1)$ :
$\displaystyle j$ | $=$ | $\displaystyle -\frac{256x^{2}w^{6}-256y^{4}w^{4}-z^{8}+48z^{5}w^{3}-512z^{2}w^{6}}{w^{6}z^{2}}$ |
Map of degree 1 from the embedded model of this modular curve to the plane model of the modular curve 12.36.2.a.1 :
$\displaystyle X$ | $=$ | $\displaystyle y$ |
$\displaystyle Y$ | $=$ | $\displaystyle z$ |
$\displaystyle Z$ | $=$ | $\displaystyle 2w$ |
Equation of the image curve:
$0$ | $=$ | $ 2X^{4}Y+X^{2}Y^{2}Z+Z^{5} $ |
Map of degree 1 from the embedded model of this modular curve to the Weierstrass model of the modular curve 12.36.2.a.1 :
$\displaystyle X$ | $=$ | $\displaystyle \frac{1}{2}y$ |
$\displaystyle Y$ | $=$ | $\displaystyle \frac{1}{8}y^{3}+\frac{1}{4}yzw$ |
$\displaystyle Z$ | $=$ | $\displaystyle w$ |
Modular covers
The following modular covers realize this modular curve as a fiber product over $X(1)$.
Factor curve | Level | Index | Degree | Genus | Rank |
---|---|---|---|---|---|
$X_{\mathrm{ns}}^+(3)$ | $3$ | $24$ | $12$ | $0$ | $0$ |
28.24.0-4.a.1.2 | $28$ | $3$ | $3$ | $0$ | $0$ |
This modular curve minimally covers the modular curves listed below.
Covered curve | Level | Index | Degree | Genus | Rank |
---|---|---|---|---|---|
28.24.0-4.a.1.2 | $28$ | $3$ | $3$ | $0$ | $0$ |
84.36.1-6.a.1.1 | $84$ | $2$ | $2$ | $1$ | $?$ |
84.36.1-6.a.1.5 | $84$ | $2$ | $2$ | $1$ | $?$ |
This modular curve is minimally covered by the modular curves in the database listed below.