gp: [N,k,chi] = [42,4,Mod(25,42)]
mf = mfinit([N,k,chi],0)
lf = mfeigenbasis(mf)
magma: //Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("42.25");
S:= CuspForms(chi, 4);
N := Newforms(S);
sage: from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(42, base_ring=CyclotomicField(6))
chi = DirichletCharacter(H, H._module([0, 4]))
N = Newforms(chi, 4, names="a")
Newform invariants
sage: traces = [2,2,-3]
f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(3)] == 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 primitive root of unity ζ 6 \zeta_{6} ζ 6 .
We also show the integral q q q -expansion of the trace form .
Character values
We give the values of χ \chi χ on generators for ( Z / 42 Z ) × \left(\mathbb{Z}/42\mathbb{Z}\right)^\times ( Z / 4 2 Z ) × .
n n n
29 29 2 9
31 31 3 1
χ ( n ) \chi(n) χ ( n )
1 1 1
− 1 + ζ 6 -1 + \zeta_{6} − 1 + ζ 6
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 kernel of the linear operator
T 5 2 − 6 T 5 + 36 T_{5}^{2} - 6T_{5} + 36 T 5 2 − 6 T 5 + 3 6
T5^2 - 6*T5 + 36
acting on S 4 n e w ( 42 , [ χ ] ) S_{4}^{\mathrm{new}}(42, [\chi]) S 4 n e w ( 4 2 , [ χ ] ) .
p p p
F p ( T ) F_p(T) F p ( T )
2 2 2
T 2 − 2 T + 4 T^{2} - 2T + 4 T 2 − 2 T + 4
T^2 - 2*T + 4
3 3 3
T 2 + 3 T + 9 T^{2} + 3T + 9 T 2 + 3 T + 9
T^2 + 3*T + 9
5 5 5
T 2 − 6 T + 36 T^{2} - 6T + 36 T 2 − 6 T + 3 6
T^2 - 6*T + 36
7 7 7
T 2 + 7 T + 343 T^{2} + 7T + 343 T 2 + 7 T + 3 4 3
T^2 + 7*T + 343
11 11 1 1
T 2 − 30 T + 900 T^{2} - 30T + 900 T 2 − 3 0 T + 9 0 0
T^2 - 30*T + 900
13 13 1 3
( T − 53 ) 2 (T - 53)^{2} ( T − 5 3 ) 2
(T - 53)^2
17 17 1 7
T 2 − 84 T + 7056 T^{2} - 84T + 7056 T 2 − 8 4 T + 7 0 5 6
T^2 - 84*T + 7056
19 19 1 9
T 2 − 97 T + 9409 T^{2} - 97T + 9409 T 2 − 9 7 T + 9 4 0 9
T^2 - 97*T + 9409
23 23 2 3
T 2 + 84 T + 7056 T^{2} + 84T + 7056 T 2 + 8 4 T + 7 0 5 6
T^2 + 84*T + 7056
29 29 2 9
( T + 180 ) 2 (T + 180)^{2} ( T + 1 8 0 ) 2
(T + 180)^2
31 31 3 1
T 2 + 179 T + 32041 T^{2} + 179T + 32041 T 2 + 1 7 9 T + 3 2 0 4 1
T^2 + 179*T + 32041
37 37 3 7
T 2 − 145 T + 21025 T^{2} - 145T + 21025 T 2 − 1 4 5 T + 2 1 0 2 5
T^2 - 145*T + 21025
41 41 4 1
( T − 126 ) 2 (T - 126)^{2} ( T − 1 2 6 ) 2
(T - 126)^2
43 43 4 3
( T + 325 ) 2 (T + 325)^{2} ( T + 3 2 5 ) 2
(T + 325)^2
47 47 4 7
T 2 − 366 T + 133956 T^{2} - 366T + 133956 T 2 − 3 6 6 T + 1 3 3 9 5 6
T^2 - 366*T + 133956
53 53 5 3
T 2 − 768 T + 589824 T^{2} - 768T + 589824 T 2 − 7 6 8 T + 5 8 9 8 2 4
T^2 - 768*T + 589824
59 59 5 9
T 2 − 264 T + 69696 T^{2} - 264T + 69696 T 2 − 2 6 4 T + 6 9 6 9 6
T^2 - 264*T + 69696
61 61 6 1
T 2 + 818 T + 669124 T^{2} + 818T + 669124 T 2 + 8 1 8 T + 6 6 9 1 2 4
T^2 + 818*T + 669124
67 67 6 7
T 2 − 523 T + 273529 T^{2} - 523T + 273529 T 2 − 5 2 3 T + 2 7 3 5 2 9
T^2 - 523*T + 273529
71 71 7 1
( T + 342 ) 2 (T + 342)^{2} ( T + 3 4 2 ) 2
(T + 342)^2
73 73 7 3
T 2 − 43 T + 1849 T^{2} - 43T + 1849 T 2 − 4 3 T + 1 8 4 9
T^2 - 43*T + 1849
79 79 7 9
T 2 − 1171 T + 1371241 T^{2} - 1171 T + 1371241 T 2 − 1 1 7 1 T + 1 3 7 1 2 4 1
T^2 - 1171*T + 1371241
83 83 8 3
( T + 810 ) 2 (T + 810)^{2} ( T + 8 1 0 ) 2
(T + 810)^2
89 89 8 9
T 2 − 600 T + 360000 T^{2} - 600T + 360000 T 2 − 6 0 0 T + 3 6 0 0 0 0
T^2 - 600*T + 360000
97 97 9 7
( T − 386 ) 2 (T - 386)^{2} ( T − 3 8 6 ) 2
(T - 386)^2
show more
show less