gp: [N,k,chi] = [820,2,Mod(21,820)]
mf = mfinit([N,k,chi],0)
lf = mfeigenbasis(mf)
sage: from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(820, base_ring=CyclotomicField(20))
chi = DirichletCharacter(H, H._module([0, 0, 7]))
N = Newforms(chi, 2, names="a")
magma: //Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("820.21");
S:= CuspForms(chi, 2);
N := Newforms(S);
Newform invariants
sage: traces = [64]
f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(1)] == traces)
gp: f = lf[1] \\ Warning: the index may be different
The algebraic \(q\)-expansion of this newform has not been computed, 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.
gp: mfembed(f)
Refresh table
This newform subspace can be constructed as the kernel of the linear operator
\( T_{3}^{64} - 2 T_{3}^{63} + 2 T_{3}^{62} - 4 T_{3}^{61} + 519 T_{3}^{60} - 1044 T_{3}^{59} + \cdots + 169300154521 \)
T3^64 - 2*T3^63 + 2*T3^62 - 4*T3^61 + 519*T3^60 - 1044*T3^59 + 1058*T3^58 - 1960*T3^57 + 113871*T3^56 - 229318*T3^55 + 234600*T3^54 - 415488*T3^53 + 13854066*T3^52 - 27843732*T3^51 + 28737158*T3^50 - 49696830*T3^49 + 1032603007*T3^48 - 2068188938*T3^47 + 2160221002*T3^46 - 3672617494*T3^45 + 49322765565*T3^44 - 98488631406*T3^43 + 104859829916*T3^42 - 173425402330*T3^41 + 1541524312269*T3^40 - 3073460592546*T3^39 + 3368716437670*T3^38 - 5279022719920*T3^37 + 31804357150709*T3^36 - 63331806225584*T3^35 + 72076934210094*T3^34 - 103478430261516*T3^33 + 433871002693525*T3^32 - 858381042020358*T3^31 + 1016014811705810*T3^30 - 1302260976687292*T3^29 + 3884884389950816*T3^28 - 7518991639930238*T3^27 + 9182640029546836*T3^26 - 10439337160354342*T3^25 + 22308553568858334*T3^24 - 40973553595087492*T3^23 + 50850031554927086*T3^22 - 51775817803320644*T3^21 + 78339212190134192*T3^20 - 129043225020317516*T3^19 + 159069493141459904*T3^18 - 147605820758274460*T3^17 + 154673330384181598*T3^16 - 203732148040942630*T3^15 + 238167366884340020*T3^14 - 204859320206156326*T3^13 + 149030845190469741*T3^12 - 122112780614232846*T3^11 + 114496704671261936*T3^10 - 89991281944021094*T3^9 + 51560690763030174*T3^8 - 20589857290536026*T3^7 + 5685252898772130*T3^6 - 1098223799599778*T3^5 + 190601715348465*T3^4 - 45755419833892*T3^3 + 12109331096258*T3^2 - 2024900800406*T3 + 169300154521
acting on \(S_{2}^{\mathrm{new}}(820, [\chi])\).