[N,k,chi] = [690,2,Mod(7,690)]
mf = mfinit([N,k,chi],0)
lf = mfeigenbasis(mf)
from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(690, base_ring=CyclotomicField(44))
chi = DirichletCharacter(H, H._module([0, 11, 38]))
N = Newforms(chi, 2, names="a")
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("690.7");
S:= CuspForms(chi, 2);
N := Newforms(S);
Newform invariants
sage: f = N[0] # Warning: the index may be different
gp: f = lf[1] \\ Warning: the index may be different
The dimension is sufficiently large that we do not compute an algebraic \(q\)-expansion, but we have computed the trace expansion.
For each embedding \(\iota_m\) of the coefficient field, the values \(\iota_m(a_n)\) are shown below.
For more information on an embedded modular form you can click on its label.
This newform subspace can be constructed as the kernel of the linear operator
\( T_{7}^{240} + 88 T_{7}^{237} - 1408 T_{7}^{236} + 924 T_{7}^{235} + 3872 T_{7}^{234} - 121308 T_{7}^{233} + 966606 T_{7}^{232} - 1414952 T_{7}^{231} - 4796440 T_{7}^{230} + 77828432 T_{7}^{229} + \cdots + 55\!\cdots\!96 \)
acting on \(S_{2}^{\mathrm{new}}(690, [\chi])\).