// Make newform 560.2.g.f in Magma, downloaded from the LMFDB on 28 March 2024. // To make the character of type GrpDrchElt, type "MakeCharacter_560_g();" // To make the character of type GrpDrchElt with Codomain the HeckeField, type "MakeCharacter_560_g_Hecke();" // To make the coeffs of the qexp of the newform in the Hecke field type "qexpCoeffs();" // To make the newform (type ModFrm), type "MakeNewformModFrm_560_2_g_f();". // This may take a long time! To see verbose output, uncomment the SetVerbose lines below. // The precision argument determines an initial guess on how many Fourier coefficients to use. // This guess is increased enough to uniquely determine the newform. // To make the Hecke irreducible modular symbols subspace (type ModSym) // containing the newform, type "MakeNewformModSym_560_2_g_f();". // This may take a long time! To see verbose output, uncomment the SetVerbose line below. // The default sign is -1. You can change this with the optional parameter "sign". function ConvertToHeckeField(input: pass_field := false, Kf := []) if not pass_field then poly := [8, -20, 25, -4, 0, 0, 1]; Kf := NumberField(Polynomial([elt : elt in poly])); AssignNames(~Kf, ["nu"]); end if; Rf_num := [[1, 0, 0, 0, 0, 0], [0, 1, 0, 0, 0, 0], [100, -121, 10, -25, -2, -5], [223, 0, -14, 35, 27, 7], [258, -605, 50, -4, -10, -25], [574, -1331, 372, 38, -26, -65]]; Rf_basisdens := [1, 1, 121, 121, 242, 242]; Rf_basisnums := ChangeUniverse([[z : z in elt] : elt in Rf_num], Kf); Rfbasis := [Rf_basisnums[i]/Rf_basisdens[i] : i in [1..Degree(Kf)]]; inp_vec := Vector(Rfbasis)*ChangeRing(Transpose(Matrix([[elt : elt in row] : row in input])),Kf); return Eltseq(inp_vec); end function; // To make the character of type GrpDrchElt, type "MakeCharacter_560_g();" function MakeCharacter_560_g() N := 560; order := 2; char_gens := [351, 421, 337, 241]; v := [2, 2, 1, 2]; // chi(gens[i]) = zeta^v[i] assert UnitGenerators(DirichletGroup(N)) eq char_gens; F := CyclotomicField(order); chi := DirichletCharacterFromValuesOnUnitGenerators(DirichletGroup(N,F),[F|F.1^e:e in v]); return MinimalBaseRingCharacter(chi); end function; // To make the character of type GrpDrchElt with Codomain the HeckeField, type "MakeCharacter_560_g_Hecke();" function MakeCharacter_560_g_Hecke(Kf) N := 560; order := 2; char_gens := [351, 421, 337, 241]; char_values := [[1, 0, 0, 0, 0, 0], [1, 0, 0, 0, 0, 0], [-1, 0, 0, 0, 0, 0], [1, 0, 0, 0, 0, 0]]; assert UnitGenerators(DirichletGroup(N)) eq char_gens; values := ConvertToHeckeField(char_values : pass_field := true, Kf := Kf); // the value of chi on the gens as elements in the Hecke field F := Universe(values);// the Hecke field chi := DirichletCharacterFromValuesOnUnitGenerators(DirichletGroup(N,F),values); return chi; end function; function ExtendMultiplicatively(weight, aps, character) prec := NextPrime(NthPrime(#aps)) - 1; // we will able to figure out a_0 ... a_prec primes := PrimesUpTo(prec); prime_powers := primes; assert #primes eq #aps; log_prec := Floor(Log(prec)/Log(2)); // prec < 2^(log_prec+1) F := Universe(aps); FXY := PolynomialRing(F, 2); // 1/(1 - a_p T + p^(weight - 1) * char(p) T^2) = 1 + a_p T + a_{p^2} T^2 + ... R := PowerSeriesRing(FXY : Precision := log_prec + 1); recursion := Coefficients(1/(1 - X*T + Y*T^2)); coeffs := [F!0: i in [1..(prec+1)]]; coeffs[1] := 1; //a_1 for i := 1 to #primes do p := primes[i]; coeffs[p] := aps[i]; b := p^(weight - 1) * F!character(p); r := 2; p_power := p * p; //deals with powers of p while p_power le prec do Append(~prime_powers, p_power); coeffs[p_power] := Evaluate(recursion[r + 1], [aps[i], b]); p_power *:= p; r +:= 1; end while; end for; Sort(~prime_powers); for pp in prime_powers do for k := 1 to Floor(prec/pp) do if GCD(k, pp) eq 1 then coeffs[pp*k] := coeffs[pp]*coeffs[k]; end if; end for; end for; return coeffs; end function; function qexpCoeffs() // To make the coeffs of the qexp of the newform in the Hecke field type "qexpCoeffs();" weight := 2; raw_aps := [[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, -1], [0, 0, 1, 0, 0, 1], [0, 0, 0, 0, 1, 0], [-2, 1, 1, 1, 0, 0], [0, -2, 2, 0, 2, 1], [0, -1, 1, 0, 0, -1], [2, 1, 1, 2, 0, 0], [0, -2, 2, 0, 2, 0], [0, 3, 3, 3, 0, 0], [-4, 0, 0, -2, 0, 0], [0, 0, 0, 0, -6, 0], [6, 2, 2, 0, 0, 0], [0, 2, -2, 0, 0, 0], [0, -3, 3, 0, -2, 3], [0, 2, -2, 0, 2, -4], [2, -3, -3, 0, 0, 0], [8, -1, -1, 0, 0, 0], [0, -2, 2, 0, -4, -2], [-2, 0, 0, -2, 0, 0], [0, 2, -2, 0, -2, 0], [4, -1, -1, -5, 0, 0], [0, -1, 1, 0, 6, 6], [-2, -2, -2, -6, 0, 0], [0, -1, 1, 0, 4, 3], [0, 3, 3, 4, 0, 0], [0, -1, 1, 0, -2, 1], [0, 0, 0, 0, 0, 0], [-4, -3, -3, -7, 0, 0], [0, 0, 0, 0, 6, -4], [0, 6, -6, 0, -2, -8], [2, 1, 1, 4, 0, 0], [0, 4, -4, 0, 0, 0], [-2, -5, -5, -8, 0, 0], [10, 0, 0, 4, 0, 0], [-2, 1, 1, -1, 0, 0], [0, 3, -3, 0, -4, -2], [0, 0, 0, 0, -4, 2], [0, -3, 3, 0, -14, -1], [0, -2, 2, 0, 14, -1], [4, 4, 4, 0, 0, 0], [-8, -3, -3, -2, 0, 0], [4, -1, -1, 3, 0, 0], [0, 2, -2, 0, -10, -6], [0, -2, 2, 0, -14, -8], [12, 8, 8, 2, 0, 0], [2, 1, 1, 7, 0, 0], [0, 1, -1, 0, 6, 1], [0, -4, 4, 0, -8, 1], [-16, 1, 1, -2, 0, 0], [0, 0, 0, 0, -4, -4], [-14, -1, -1, -3, 0, 0], [2, 2, 2, 0, 0, 0], [10, -3, -3, 8, 0, 0], [0, -2, 2, 0, -6, 0], [0, -4, 4, 0, 8, 0], [8, 3, 3, -2, 0, 0], [4, -8, -8, -8, 0, 0], [0, -2, 2, 0, 10, 4], [-16, 3, 3, 5, 0, 0], [0, -2, 2, 0, -4, 9], [0, 4, -4, 0, 10, 3], [0, -2, 2, 0, -28, 3], [12, 4, 4, 4, 0, 0], [0, -5, 5, 0, -8, -5], [0, 0, 0, 0, -22, -2], [8, 2, 2, -4, 0, 0], [0, 4, -4, 0, -2, -4], [0, 12, -12, 0, -8, -6], [-12, -7, -7, -8, 0, 0], [0, -5, 5, 0, -12, 9], [8, 4, 4, 4, 0, 0], [0, 3, -3, 0, -2, -13], [0, 4, -4, 0, 6, 2], [-4, -2, -2, 0, 0, 0], [0, -2, 2, 0, 0, 0], [20, 1, 1, 9, 0, 0], [0, 2, -2, 0, 2, 1], [-6, 3, 3, 1, 0, 0], [-2, 4, 4, 2, 0, 0], [-6, 9, 9, 12, 0, 0], [8, -7, -7, -13, 0, 0], [-6, -9, -9, -11, 0, 0], [0, -4, 4, 0, -22, 0], [-12, 2, 2, -6, 0, 0], [0, 4, -4, 0, 0, -8], [0, 1, 1, 7, 0, 0], [0, -8, 8, 0, -6, 16], [-4, -9, -9, -4, 0, 0], [0, 0, 0, 0, 0, 8], [0, 4, -4, 0, 0, -5], [0, 4, 4, -10, 0, 0], [0, -6, 6, 0, 18, 4], [-18, -7, -7, -9, 0, 0], [14, -7, -7, 11, 0, 0], [0, 3, -3, 0, 10, -5], [-16, 1, 1, -2, 0, 0], [10, -4, -4, -6, 0, 0], [0, 9, -9, 0, -6, -14], [8, -5, -5, 5, 0, 0], [0, -10, 10, 0, 8, 12], [0, 4, -4, 0, -2, 2], [0, -5, 5, 0, 22, 2], [4, -2, -2, -10, 0, 0], [-20, -2, -2, -8, 0, 0], [0, 3, -3, 0, 12, -7], [0, -7, 7, 0, 10, 2], [0, 5, -5, 0, 0, 7], [-4, -15, -15, -7, 0, 0], [2, 2, 2, 10, 0, 0], [0, 5, -5, 0, -2, 9], [0, 6, -6, 0, 6, -6], [0, -16, 16, 0, 10, 8], [34, 1, 1, 4, 0, 0], [4, -1, -1, 3, 0, 0], [-4, -10, -10, 6, 0, 0], [0, -8, 8, 0, 8, 7], [0, 2, -2, 0, 0, 8], [0, -2, 2, 0, 18, 10], [6, -5, -5, -9, 0, 0], [8, 5, 5, -8, 0, 0], [0, -8, 8, 0, -24, 12], [0, 0, 0, 0, -10, 11], [0, 4, -4, 0, 16, -4], [-10, 11, 11, 2, 0, 0], [8, 5, 5, 13, 0, 0], [-12, -1, -1, -9, 0, 0], [-12, 8, 8, -2, 0, 0], [0, 6, -6, 0, 4, -8], [0, 10, -10, 0, -18, -11], [14, 15, 15, 11, 0, 0], [0, 2, -2, 0, -2, -4], [-2, -7, -7, 3, 0, 0], [0, -2, 2, 0, -6, -6], [26, -2, -2, 4, 0, 0], [-30, 4, 4, 10, 0, 0], [0, -8, 8, 0, 14, 9], [0, -2, 2, 0, -4, 5], [0, -4, 4, 0, -6, -3], [-6, -11, -11, -13, 0, 0], [2, -3, -3, -4, 0, 0], [0, 5, 5, -1, 0, 0], [0, -10, 10, 0, -20, 6], [0, 6, -6, 0, 16, -2], [12, 3, 3, -2, 0, 0], [-16, 8, 8, 2, 0, 0], [0, -11, 11, 0, -4, 6], [0, -4, 4, 0, 2, -4], [6, 11, 11, -6, 0, 0], [0, -6, 6, 0, 36, -2], [0, -6, 6, 0, 2, -2], [-10, -2, -2, -18, 0, 0], [0, -20, 20, 0, 16, 8], [0, 2, -2, 0, 16, 4], [0, -2, 2, 0, 4, -14], [16, -12, -12, 4, 0, 0], [36, -5, -5, -5, 0, 0], [-10, -6, -6, -20, 0, 0], [0, -11, 11, 0, 12, 15], [24, 9, 9, 16, 0, 0], [0, 0, 0, 0, -24, -2], [0, 2, -2, 0, -8, 6], [0, -12, 12, 0, 18, 2], [-10, -5, -5, -8, 0, 0], [0, 4, -4, 0, 8, -8], [0, 13, -13, 0, 6, 3], [-14, 12, 12, 10, 0, 0], [0, -6, 6, 0, -2, 9]]; aps := ConvertToHeckeField(raw_aps); chi := MakeCharacter_560_g_Hecke(Universe(aps)); return ExtendMultiplicatively(weight, aps, chi); end function; // To make the newform (type ModFrm), type "MakeNewformModFrm_560_2_g_f();". // This may take a long time! To see verbose output, uncomment the SetVerbose lines below. // The precision argument determines an initial guess on how many Fourier coefficients to use. // This guess is increased enough to uniquely determine the newform. function MakeNewformModFrm_560_2_g_f(:prec:=6) chi := MakeCharacter_560_g(); f_vec := qexpCoeffs(); Kf := Universe(f_vec); // SetVerbose("ModularForms", true); // SetVerbose("ModularSymbols", true); S := CuspidalSubspace(ModularForms(chi, 2)); S := BaseChange(S, Kf); maxprec := NextPrime(997) - 1; while true do trunc_vec := Vector(Kf, [0] cat [f_vec[i]: i in [1..prec]]); B := Basis(S, prec + 1); S_basismat := Matrix([AbsEltseq(g): g in B]); if Rank(S_basismat) eq Min(NumberOfRows(S_basismat), NumberOfColumns(S_basismat)) then S_basismat := ChangeRing(S_basismat,Kf); f_lincom := Solution(S_basismat,trunc_vec); f := &+[f_lincom[i]*Basis(S)[i] : i in [1..#Basis(S)]]; return f; end if; error if prec eq maxprec, "Unable to distinguish newform within newspace"; prec := Min(Ceiling(1.25 * prec), maxprec); end while; end function; // To make the Hecke irreducible modular symbols subspace (type ModSym) // containing the newform, type "MakeNewformModSym_560_2_g_f();". // This may take a long time! To see verbose output, uncomment the SetVerbose line below. // The default sign is -1. You can change this with the optional parameter "sign". function MakeNewformModSym_560_2_g_f( : sign := -1) R := PolynomialRing(Rationals()); chi := MakeCharacter_560_g(); // SetVerbose("ModularSymbols", true); Snew := NewSubspace(CuspidalSubspace(ModularSymbols(chi,2,sign))); Vf := Kernel([<3,R![4, 0, 32, 0, 13, 0, 1]>,<11,R![-8, 8, 7, 1]>],Snew); return Vf; end function;