gp: [N,k,chi] = [1920,2,Mod(959,1920)]
mf = mfinit([N,k,chi],0)
lf = mfeigenbasis(mf)
sage: from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(1920, base_ring=CyclotomicField(2))
chi = DirichletCharacter(H, H._module([1, 1, 1, 1]))
N = Newforms(chi, 2, names="a")
magma: //Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("1920.959");
S:= CuspForms(chi, 2);
N := Newforms(S);
Newform invariants
sage: traces = [4,0,-2,0,-4,0,-4,0,0,0,0,0,8,0,-2]
f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(15)] == traces)
gp: f = lf[1] \\ Warning: the index may be different
sage: f.q_expansion() # note that sage often uses an isomorphic number field
gp: mfcoefs(f, 20)
Coefficients of the q q q -expansion are expressed in terms of a basis 1 , β 1 , β 2 , β 3 1,\beta_1,\beta_2,\beta_3 1 , β 1 , β 2 , β 3 for the coefficient ring described below.
We also show the integral q q q -expansion of the trace form .
Basis of coefficient ring in terms of a root ν \nu ν of
x 4 + 3 x 2 + 1 x^{4} + 3x^{2} + 1 x 4 + 3 x 2 + 1
x^4 + 3*x^2 + 1
:
β 1 \beta_{1} β 1 = = =
ν 3 + ν 2 + 3 ν + 1 \nu^{3} + \nu^{2} + 3\nu + 1 ν 3 + ν 2 + 3 ν + 1
v^3 + v^2 + 3*v + 1
β 2 \beta_{2} β 2 = = =
− 2 ν 3 − 4 ν -2\nu^{3} - 4\nu − 2 ν 3 − 4 ν
-2*v^3 - 4*v
β 3 \beta_{3} β 3 = = =
− ν 3 + ν 2 − 3 ν + 2 -\nu^{3} + \nu^{2} - 3\nu + 2 − ν 3 + ν 2 − 3 ν + 2
-v^3 + v^2 - 3*v + 2
ν \nu ν = = =
( − β 3 + β 2 + β 1 + 1 ) / 2 ( -\beta_{3} + \beta_{2} + \beta _1 + 1 ) / 2 ( − β 3 + β 2 + β 1 + 1 ) / 2
(-b3 + b2 + b1 + 1) / 2
ν 2 \nu^{2} ν 2 = = =
( β 3 + β 1 − 3 ) / 2 ( \beta_{3} + \beta _1 - 3 ) / 2 ( β 3 + β 1 − 3 ) / 2
(b3 + b1 - 3) / 2
ν 3 \nu^{3} ν 3 = = =
( 2 β 3 − 3 β 2 − 2 β 1 − 2 ) / 2 ( 2\beta_{3} - 3\beta_{2} - 2\beta _1 - 2 ) / 2 ( 2 β 3 − 3 β 2 − 2 β 1 − 2 ) / 2
(2*b3 - 3*b2 - 2*b1 - 2) / 2
Character values
We give the values of χ \chi χ on generators for ( Z / 1920 Z ) × \left(\mathbb{Z}/1920\mathbb{Z}\right)^\times ( Z / 1 9 2 0 Z ) × .
n n n
511 511 5 1 1
641 641 6 4 1
901 901 9 0 1
1537 1537 1 5 3 7
χ ( n ) \chi(n) χ ( n )
− 1 -1 − 1
− 1 -1 − 1
− 1 -1 − 1
− 1 -1 − 1
For each embedding ι m \iota_m ι m of the coefficient field, the values ι m ( a n ) \iota_m(a_n) ι m ( a n ) are shown below.
For more information on an embedded modular form you can click on its label.
gp: mfembed(f)
Refresh table
This newform subspace can be constructed as the intersection of the kernels of the following linear operators acting on S 2 n e w ( 1920 , [ χ ] ) S_{2}^{\mathrm{new}}(1920, [\chi]) S 2 n e w ( 1 9 2 0 , [ χ ] ) :
T 7 2 + 2 T 7 − 4 T_{7}^{2} + 2T_{7} - 4 T 7 2 + 2 T 7 − 4
T7^2 + 2*T7 - 4
T 13 2 − 4 T 13 − 16 T_{13}^{2} - 4T_{13} - 16 T 1 3 2 − 4 T 1 3 − 1 6
T13^2 - 4*T13 - 16
T 17 2 + 4 T 17 − 16 T_{17}^{2} + 4T_{17} - 16 T 1 7 2 + 4 T 1 7 − 1 6
T17^2 + 4*T17 - 16
T 19 2 + 4 T 19 − 16 T_{19}^{2} + 4T_{19} - 16 T 1 9 2 + 4 T 1 9 − 1 6
T19^2 + 4*T19 - 16
T 29 2 − 20 T_{29}^{2} - 20 T 2 9 2 − 2 0
T29^2 - 20
T 83 2 − 6 T 83 − 116 T_{83}^{2} - 6T_{83} - 116 T 8 3 2 − 6 T 8 3 − 1 1 6
T83^2 - 6*T83 - 116
p p p
F p ( T ) F_p(T) F p ( T )
2 2 2
T 4 T^{4} T 4
T^4
3 3 3
T 4 + 2 T 3 + ⋯ + 9 T^{4} + 2 T^{3} + \cdots + 9 T 4 + 2 T 3 + ⋯ + 9
T^4 + 2*T^3 + 2*T^2 + 6*T + 9
5 5 5
( T 2 + 2 T + 5 ) 2 (T^{2} + 2 T + 5)^{2} ( T 2 + 2 T + 5 ) 2
(T^2 + 2*T + 5)^2
7 7 7
( T 2 + 2 T − 4 ) 2 (T^{2} + 2 T - 4)^{2} ( T 2 + 2 T − 4 ) 2
(T^2 + 2*T - 4)^2
11 11 1 1
( T 2 + 16 ) 2 (T^{2} + 16)^{2} ( T 2 + 1 6 ) 2
(T^2 + 16)^2
13 13 1 3
( T 2 − 4 T − 16 ) 2 (T^{2} - 4 T - 16)^{2} ( T 2 − 4 T − 1 6 ) 2
(T^2 - 4*T - 16)^2
17 17 1 7
( T 2 + 4 T − 16 ) 2 (T^{2} + 4 T - 16)^{2} ( T 2 + 4 T − 1 6 ) 2
(T^2 + 4*T - 16)^2
19 19 1 9
( T 2 + 4 T − 16 ) 2 (T^{2} + 4 T - 16)^{2} ( T 2 + 4 T − 1 6 ) 2
(T^2 + 4*T - 16)^2
23 23 2 3
T 4 + 12 T 2 + 16 T^{4} + 12T^{2} + 16 T 4 + 1 2 T 2 + 1 6
T^4 + 12*T^2 + 16
29 29 2 9
( T 2 − 20 ) 2 (T^{2} - 20)^{2} ( T 2 − 2 0 ) 2
(T^2 - 20)^2
31 31 3 1
T 4 + 48 T 2 + 256 T^{4} + 48T^{2} + 256 T 4 + 4 8 T 2 + 2 5 6
T^4 + 48*T^2 + 256
37 37 3 7
( T 2 + 12 T + 16 ) 2 (T^{2} + 12 T + 16)^{2} ( T 2 + 1 2 T + 1 6 ) 2
(T^2 + 12*T + 16)^2
41 41 4 1
( T 2 + 16 ) 2 (T^{2} + 16)^{2} ( T 2 + 1 6 ) 2
(T^2 + 16)^2
43 43 4 3
T 4 + 108 T 2 + 1936 T^{4} + 108T^{2} + 1936 T 4 + 1 0 8 T 2 + 1 9 3 6
T^4 + 108*T^2 + 1936
47 47 4 7
T 4 + 108 T 2 + 1936 T^{4} + 108T^{2} + 1936 T 4 + 1 0 8 T 2 + 1 9 3 6
T^4 + 108*T^2 + 1936
53 53 5 3
( T 2 + 80 ) 2 (T^{2} + 80)^{2} ( T 2 + 8 0 ) 2
(T^2 + 80)^2
59 59 5 9
( T 2 + 80 ) 2 (T^{2} + 80)^{2} ( T 2 + 8 0 ) 2
(T^2 + 80)^2
61 61 6 1
T 4 + 192 T 2 + 4096 T^{4} + 192T^{2} + 4096 T 4 + 1 9 2 T 2 + 4 0 9 6
T^4 + 192*T^2 + 4096
67 67 6 7
T 4 + 140 T 2 + 400 T^{4} + 140T^{2} + 400 T 4 + 1 4 0 T 2 + 4 0 0
T^4 + 140*T^2 + 400
71 71 7 1
T 4 T^{4} T 4
T^4
73 73 7 3
T 4 + 192 T 2 + 4096 T^{4} + 192T^{2} + 4096 T 4 + 1 9 2 T 2 + 4 0 9 6
T^4 + 192*T^2 + 4096
79 79 7 9
T 4 + 112 T 2 + 256 T^{4} + 112T^{2} + 256 T 4 + 1 1 2 T 2 + 2 5 6
T^4 + 112*T^2 + 256
83 83 8 3
( T 2 − 6 T − 116 ) 2 (T^{2} - 6 T - 116)^{2} ( T 2 − 6 T − 1 1 6 ) 2
(T^2 - 6*T - 116)^2
89 89 8 9
( T 2 + 64 ) 2 (T^{2} + 64)^{2} ( T 2 + 6 4 ) 2
(T^2 + 64)^2
97 97 9 7
T 4 + 192 T 2 + 4096 T^{4} + 192T^{2} + 4096 T 4 + 1 9 2 T 2 + 4 0 9 6
T^4 + 192*T^2 + 4096
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