[N,k,chi] = [931,2,Mod(134,931)]
mf = mfinit([N,k,chi],0)
lf = mfeigenbasis(mf)
from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(931, base_ring=CyclotomicField(14))
chi = DirichletCharacter(H, H._module([4, 0]))
N = Newforms(chi, 2, names="a")
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("931.134");
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
\( T_{2}^{240} - 3 T_{2}^{239} + 63 T_{2}^{238} - 187 T_{2}^{237} + 2144 T_{2}^{236} - 6289 T_{2}^{235} + 52257 T_{2}^{234} - 150606 T_{2}^{233} + 1019210 T_{2}^{232} - 2872776 T_{2}^{231} + 16873139 T_{2}^{230} + \cdots + 12\!\cdots\!29 \)
acting on \(S_{2}^{\mathrm{new}}(931, [\chi])\).