Properties

Label 38.40.2.a.1
Level $38$
Index $40$
Genus $2$
Analytic rank $0$
Cusps $2$
$\Q$-cusps $2$

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Invariants

Level: $38$ $\SL_2$-level: $38$ Newform level: $76$
Index: $40$ $\PSL_2$-index:$40$
Genus: $2 = 1 + \frac{ 40 }{12} - \frac{ 0 }{4} - \frac{ 4 }{3} - \frac{ 2 }{2}$
Cusps: $2$ (all of which are rational) Cusp widths $2\cdot38$ Cusp orbits $1^{2}$
Elliptic points: $0$ of order $2$ and $4$ of order $3$
Analytic rank: $0$
$\Q$-gonality: $2$
$\overline{\Q}$-gonality: $2$
Rational cusps: $2$
Rational CM points: none

Other labels

Cummins and Pauli (CP) label: 38A2
Rouse, Sutherland, and Zureick-Brown (RSZB) label: 38.40.2.1

Level structure

$\GL_2(\Z/38\Z)$-generators: $\begin{bmatrix}17&34\\26&11\end{bmatrix}$, $\begin{bmatrix}26&11\\37&15\end{bmatrix}$, $\begin{bmatrix}32&1\\17&37\end{bmatrix}$
Contains $-I$: yes
Quadratic refinements: 38.80.2-38.a.1.1, 38.80.2-38.a.1.2, 76.80.2-38.a.1.1, 76.80.2-38.a.1.2, 76.80.2-38.a.1.3, 76.80.2-38.a.1.4, 114.80.2-38.a.1.1, 114.80.2-38.a.1.2, 152.80.2-38.a.1.1, 152.80.2-38.a.1.2, 152.80.2-38.a.1.3, 152.80.2-38.a.1.4, 152.80.2-38.a.1.5, 152.80.2-38.a.1.6, 190.80.2-38.a.1.1, 190.80.2-38.a.1.2, 228.80.2-38.a.1.1, 228.80.2-38.a.1.2, 228.80.2-38.a.1.3, 228.80.2-38.a.1.4, 266.80.2-38.a.1.1, 266.80.2-38.a.1.2
Cyclic 38-isogeny field degree: $3$
Cyclic 38-torsion field degree: $54$
Full 38-torsion field degree: $18468$

Jacobian

Conductor: $2^{2}\cdot19^{2}$
Simple: no
Squarefree: yes
Decomposition: $1^{2}$
Newforms: 19.2.a.a, 76.2.a.a

Models

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

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

$ 0 $ $=$ $ x^{4} + 19 x^{2} y^{2} + 8 x^{2} y z - y z^{3} $
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Weierstrass model Weierstrass model

$ y^{2} + x^{3} y $ $=$ $ -4x^{4} + 16x^{2} - 19 $
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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.

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

Maps between models of this curve

Birational map from embedded model to plane model:

$\displaystyle X$ $=$ $\displaystyle y$
$\displaystyle Y$ $=$ $\displaystyle x$
$\displaystyle Z$ $=$ $\displaystyle z$

Birational map from embedded model to Weierstrass model:

$\displaystyle X$ $=$ $\displaystyle z$
$\displaystyle Y$ $=$ $\displaystyle -19xy^{2}-4y^{2}z$
$\displaystyle Z$ $=$ $\displaystyle -y$

Maps to other modular curves

$j$-invariant map of degree 40 from the embedded model of this modular curve to the modular curve $X(1)$ :

$\displaystyle j$ $=$ $\displaystyle 2\,\frac{79235168x^{6}w^{3}+161982144x^{4}w^{5}+113402944x^{2}w^{7}+955552000xyz^{7}-14954317440xyz^{5}w^{2}+57336793200xyz^{3}w^{4}-53158602336xyzw^{6}-1501942400xz^{7}w+12284940304xz^{5}w^{3}+7490403328xz^{3}w^{5}-28050431104xzw^{7}+152640000yz^{8}-3093396480yz^{6}w^{2}+12420716820yz^{4}w^{4}-15071859560yz^{2}w^{6}+3008007823yw^{8}-144633600z^{8}w+2069573764z^{6}w^{3}+11320518z^{4}w^{5}-6018944207z^{2}w^{7}+1505468192w^{9}}{438976x^{4}w^{5}-17024x^{2}w^{7}+238888xyz^{7}-813576xyz^{5}w^{2}+59026xyz^{3}w^{4}+40245xyzw^{6}+29316xz^{7}w+337496xz^{5}w^{3}-140149xz^{3}w^{5}+11520xzw^{7}+38160yz^{8}-48456yz^{6}w^{2}-69500yz^{4}w^{4}+7224yz^{2}w^{6}+600yw^{8}-24432z^{8}w+67628z^{6}w^{3}-6024z^{4}w^{5}-600z^{2}w^{7}}$

Modular covers

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Cover information

Click on a modular curve in the diagram to see information about it.

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

Factor curve Level Index Degree Genus Rank Kernel decomposition
$X_{\mathrm{ns}}(2)$ $2$ $20$ $20$ $0$ $0$ full Jacobian
$X_0(19)$ $19$ $2$ $2$ $1$ $0$ $1$

This modular curve minimally covers the modular curves listed below.

Covered curve Level Index Degree Genus Rank Kernel decomposition
$X_{\mathrm{ns}}(2)$ $2$ $20$ $20$ $0$ $0$ full Jacobian
$X_0(19)$ $19$ $2$ $2$ $1$ $0$ $1$

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

Covering curve Level Index Degree Genus Rank Kernel decomposition
38.120.4.a.1 $38$ $3$ $3$ $4$ $0$ $2$
38.120.4.a.2 $38$ $3$ $3$ $4$ $0$ $2$
38.120.4.b.1 $38$ $3$ $3$ $4$ $0$ $1^{2}$
38.120.8.a.1 $38$ $3$ $3$ $8$ $0$ $1^{6}$
38.120.8.b.1 $38$ $3$ $3$ $8$ $2$ $2^{3}$
38.120.8.c.1 $38$ $3$ $3$ $8$ $2$ $1^{2}\cdot2^{2}$
38.120.8.d.1 $38$ $3$ $3$ $8$ $0$ $2\cdot4$
38.120.8.d.2 $38$ $3$ $3$ $8$ $0$ $2\cdot4$
38.760.53.a.1 $38$ $19$ $19$ $53$ $20$ $1^{7}\cdot2^{7}\cdot3^{2}\cdot4\cdot6^{2}\cdot8$
76.80.4.a.1 $76$ $2$ $2$ $4$ $?$ not computed
76.80.4.a.2 $76$ $2$ $2$ $4$ $?$ not computed
76.160.11.a.1 $76$ $4$ $4$ $11$ $?$ not computed
114.120.10.a.1 $114$ $3$ $3$ $10$ $?$ not computed
114.160.11.a.1 $114$ $4$ $4$ $11$ $?$ not computed
152.80.4.a.1 $152$ $2$ $2$ $4$ $?$ not computed
152.80.4.a.2 $152$ $2$ $2$ $4$ $?$ not computed
190.200.14.a.1 $190$ $5$ $5$ $14$ $?$ not computed
190.240.19.a.1 $190$ $6$ $6$ $19$ $?$ not computed
228.80.4.a.1 $228$ $2$ $2$ $4$ $?$ not computed
228.80.4.a.2 $228$ $2$ $2$ $4$ $?$ not computed
266.120.4.a.1 $266$ $3$ $3$ $4$ $?$ not computed
266.120.4.a.2 $266$ $3$ $3$ $4$ $?$ not computed
266.120.4.b.1 $266$ $3$ $3$ $4$ $?$ not computed
266.120.4.b.2 $266$ $3$ $3$ $4$ $?$ not computed
266.120.4.c.1 $266$ $3$ $3$ $4$ $?$ not computed
266.120.4.c.2 $266$ $3$ $3$ $4$ $?$ not computed
266.120.8.a.1 $266$ $3$ $3$ $8$ $?$ not computed
266.120.8.b.1 $266$ $3$ $3$ $8$ $?$ not computed
266.120.8.c.1 $266$ $3$ $3$ $8$ $?$ not computed
266.120.8.d.1 $266$ $3$ $3$ $8$ $?$ not computed
266.120.8.d.2 $266$ $3$ $3$ $8$ $?$ not computed
266.120.8.e.1 $266$ $3$ $3$ $8$ $?$ not computed
266.120.8.e.2 $266$ $3$ $3$ $8$ $?$ not computed
266.120.8.f.1 $266$ $3$ $3$ $8$ $?$ not computed
266.120.8.f.2 $266$ $3$ $3$ $8$ $?$ not computed
266.320.23.a.1 $266$ $8$ $8$ $23$ $?$ not computed