
// Make newform 99.2.m.a in Magma, downloaded from the LMFDB on 09 January 2026.
// To make the character of type GrpDrchElt, type "MakeCharacter_99_m();"
// To make the character of type GrpDrchElt with Codomain the HeckeField, type "MakeCharacter_99_m_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_99_2_m_a();".
// 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_99_2_m_a();".
// 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 := [1, -1, 0, 1, -1, 1, 0, -1, 1];
        Kf := NumberField(Polynomial([elt : elt in poly]));
        AssignNames(~Kf, ["nu"]);
    end if;
    Rfbasis := [Kf.1^i : i in [0..Degree(Kf)-1]];
    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_99_m();"
function MakeCharacter_99_m()
    N := 99;
    order := 15;
    char_gens := [56, 46];
    v := [5, 3];
    // 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_99_m_Hecke();"
function MakeCharacter_99_m_Hecke( : Kf := false)
    N := 99;
    order := 15;
    char_gens := [56, 46];
    char_values := [[-1, 0, 0, 0, 0, -1, 0, 0], [-1, 0, 1, -1, 0, 0, -1, 1]];
    assert UnitGenerators(DirichletGroup(N)) eq char_gens;
    values := ConvertToHeckeField(char_values : pass_field := ISA(Type(Kf), Fld), 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<X, Y> := 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<T> := PowerSeriesRing(FXY : Precision := log_prec + 1);
    recursion := Coefficients(1/(1 - X*T + Y*T^2));
    coeffs := [F!0: i in [1..prec]];
    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 := [[1, 0, -2, 1, -1, 1, 1, -1], [0, -1, 0, 0, 0, 0, -2, 0], [2, -2, 0, 0, 0, 2, 0, 0], [-1, 0, 1, -1, 1, 0, -1, 1], [2, 2, -1, 2, -2, 0, 4, -2], [4, 0, 0, 0, -4, 4, 0, -4], [3, 0, 0, 3, 0, 0, 3, 0], [0, 0, 0, 0, 0, 0, 1, 0], [-3, -1, 0, 0, -1, -3, 0, 0], [-3, 3, 0, -3, 3, 0, 0, 3], [-1, 0, 0, 0, 1, -1, 0, 0], [2, 0, 3, 2, 0, 0, -3, 3], [4, -9, 0, 0, 0, 4, 0, -4], [-3, 3, 3, -3, 3, -3, 0, 3], [0, 1, -8, 0, 0, -8, 1, 0], [0, 0, 4, -5, 0, 0, -5, 4], [0, 1, 0, 0, 1, 0, 0, 1], [-9, 6, 0, -9, 9, -6, -3, 9], [-6, 0, 0, 0, 0, -6, 0, 0], [5, 0, 0, -6, 0, 0, 5, 0], [2, 0, -5, 2, 0, 0, 5, -5], [9, 0, -4, 9, -9, 9, 9, -9], [11, -13, 0, 11, -11, 13, -2, -11], [-8, 0, -2, 2, 0, 0, 0, -2], [0, 0, 6, 0, 0, 0, 0, 0], [-4, 0, -2, -4, 4, -4, -4, 4], [0, -2, 0, 0, -9, 0, 0, -2], [-13, 0, 13, 0, 0, 0, -7, 13], [9, 0, 3, -3, 0, 0, 0, 3], [2, 14, 0, 0, 0, 2, 0, -2], [-9, 0, 0, -5, 0, 0, -9, 0], [-18, -2, 0, 0, -2, -18, 0, 0], [8, -7, 0, 8, -8, 7, 1, -8], [0, 6, 0, 0, 6, 0, 0, 6], [1, -1, 0, 0, 9, 1, 0, 9], [0, 7, -7, 0, 0, -7, 7, 0], [-3, 12, 0, 0, 0, -3, 0, 3], [0, 0, -11, -6, 0, 0, -6, -11], [-2, 0, 0, 0, 2, -2, 0, -7], [0, 15, 5, 0, 0, 5, 15, 0], [-8, 0, 8, 0, 0, 0, -18, 8], [5, 0, 0, -13, 0, 0, 5, 0], [1, -8, 7, 1, -1, 0, -7, -1], [-11, 11, 0, 0, 11, -11, 0, 11], [7, 0, -2, 2, 0, 0, 0, -2], [-9, 0, -3, 3, 0, 0, 0, -3], [-4, 0, 0, 0, 4, -4, 0, 18], [0, -12, 17, 0, 0, 17, -12, 0], [-16, 1, 15, -16, 16, 0, -15, 16], [-10, 0, 0, 0, 10, -10, 0, 4], [0, 0, -18, 18, 0, 0, 18, -18], [4, 4, 0, 0, 0, 4, 0, -4], [24, -24, -24, 24, -24, 12, 0, -24], [0, 0, -6, -9, 0, 0, -9, -6], [0, 5, 0, 0, -18, 0, 0, 5], [6, -6, -6, 6, -6, -3, 0, -6], [-15, 0, 0, -12, 0, 0, -15, 0], [-12, 0, 14, -12, 0, 0, -14, 14], [-2, 0, -16, -2, 2, -2, -2, 2], [5, 2, 0, 5, -5, -2, 7, -5], [0, -17, 0, 0, 0, 0, 0, 0], [0, -10, 0, 0, -23, 0, 0, -10], [6, 0, -3, 3, 0, 0, 0, -3], [10, -1, 0, 0, 0, 10, 0, -10], [-1, -3, 0, -1, 1, 3, -4, 1], [8, 0, 8, 8, -8, 8, 8, -8], [-12, 12, 12, -12, 12, -5, 0, 12], [0, -4, 0, 0, -9, 0, 0, -4], [17, -17, 0, 0, -1, 17, 0, -1], [0, 9, -3, 0, 0, -3, 9, 0], [12, -12, -12, 12, -12, 3, 0, -12], [21, 0, -18, 21, 0, 0, 18, -18], [-9, 6, 3, -9, 9, 0, -3, 9], [-17, 14, 0, 0, 14, -17, 0, 0], [11, 0, 0, 9, 0, 0, 11, 0], [-3, 0, 0, 0, 3, -3, 0, 18], [-14, 14, 0, -14, 14, 0, 0, 14], [9, 0, 18, -18, 0, 0, 0, 18], [0, 0, 0, 0, -9, 0, 0, -9], [19, 0, 0, 0, -19, 19, 0, -22], [0, -5, 0, 0, -5, 0, 0, 0], [0, -7, -2, 0, 0, -2, -7, 0], [0, 0, -8, 26, 0, 0, 26, -8], [-3, 0, -16, -3, 0, 0, 16, -16], [6, -6, -6, 6, -6, 9, 0, -6], [0, -2, 2, 0, 0, 2, -2, 0], [0, 0, -1, -4, 0, 0, -4, -1], [1, -1, 0, 1, -1, 1, 0, -1], [-3, 3, 3, -3, 3, -21, 0, 3], [-17, 0, 0, 0, 0, -17, 0, 0], [2, 0, 0, -2, 0, 0, 2, 0], [13, -15, 0, 13, -13, 15, -2, -13], [21, 0, -21, 0, 0, 0, 21, -21], [0, 7, 0, 0, 3, 0, 0, 7], [0, 12, 0, 0, 31, 0, 0, 12], [-4, 0, 4, 0, 0, 0, -16, 4], [-10, -11, 0, 0, 0, -10, 0, 10], [28, 0, -8, 28, 0, 0, 8, -8], [0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 20, -5, 0, 0, -5, 20], [0, 21, 7, 0, 0, 7, 21, 0], [-8, 0, 22, -8, 0, 0, -22, 22], [28, 0, 0, 0, -28, 28, 0, -3], [0, -21, -11, 0, 0, -11, -21, 0], [25, -4, 0, 0, -4, 25, 0, 0], [12, 0, 0, 28, 0, 0, 12, 0], [6, -12, 6, 6, -6, 0, -6, -6], [-6, 0, 8, -8, 0, 0, 0, 8], [19, -19, 0, 0, 1, 19, 0, 1], [-15, 4, 11, -15, 15, 0, -11, 15], [-12, 0, 0, 0, 12, -12, 0, -11], [-3, 0, 3, 0, 0, 0, 15, 3], [-23, 31, 0, 0, 31, -23, 0, 0], [0, -13, -9, 0, 0, -9, -13, 0], [1, 0, 15, 1, 0, 0, -15, 15], [0, -20, 25, 0, 0, 25, -20, 0], [-2, 2, 0, 0, 5, -2, 0, 5], [0, 0, -12, 10, 0, 0, 10, -12], [0, -20, 0, 0, 11, 0, 0, -20], [-21, 21, 21, -21, 21, -24, 0, 21], [14, -6, 0, 0, -6, 14, 0, 0], [-9, 0, -15, -9, 9, -9, -9, 9], [-11, 19, 0, -11, 11, -19, 8, 11], [-8, 0, -4, 4, 0, 0, 0, -4], [22, 0, -21, 22, -22, 22, 22, -22], [40, 0, -40, 0, 0, 0, 17, -40], [27, -29, 0, 27, -27, 29, -2, -27], [6, 0, 16, 6, 0, 0, -16, 16], [-24, 24, 24, -24, 24, -20, 0, 24], [0, 4, 0, 0, 46, 0, 0, 4], [0, 0, 6, -30, 0, 0, -30, 6], [-10, 10, 0, 0, 30, -10, 0, 30], [-36, 27, 0, 0, 0, -36, 0, 36], [0, 0, -11, 0, 0, 0, 0, -11], [-21, 0, 0, 0, 21, -21, 0, -6], [-2, 11, 0, 0, 11, -2, 0, 0], [-14, 0, 14, 0, 0, 0, 1, 14], [36, -36, 0, 0, -36, 36, 0, -36], [0, 0, 0, 0, -15, 0, 0, -15], [-5, 0, 0, -15, 0, 0, -5, 0], [-27, 0, 27, 0, 0, 0, -35, 27], [24, -23, -1, 24, -24, 0, 1, -24], [-6, 0, 0, 0, 6, -6, 0, -46], [0, 0, 36, 13, 0, 0, 13, 36], [-25, 0, -5, -25, 0, 0, 5, -5], [0, 27, -6, 0, 0, -6, 27, 0], [41, -50, 0, 41, -41, 50, -9, -41], [-20, 20, 20, -20, 20, -7, 0, 20], [18, 9, 0, 0, 9, 18, 0, 0], [25, 0, 0, -1, 0, 0, 25, 0], [22, -24, 0, 0, 0, 22, 0, -22], [8, 0, 10, -10, 0, 0, 0, 10], [14, 0, -14, 0, 0, 0, -13, -14], [0, -13, 0, 0, 4, 0, 0, -13], [22, -34, 0, 22, -22, 34, -12, -22], [-10, 0, -3, -10, 10, -10, -10, 10], [-37, 0, 0, -4, 0, 0, -37, 0], [39, -24, 0, 39, -39, 24, 15, -39], [0, 0, 2, 13, 0, 0, 13, 2], [-23, 23, 0, 0, -8, -23, 0, -8], [-6, 6, 6, -6, 6, 27, 0, 6], [20, 0, -37, 20, 0, 0, 37, -37], [9, -38, 0, 0, -38, 9, 0, 0], [-15, 0, 15, 0, 0, 0, -15, 15], [2, 0, 0, 0, -2, 2, 0, 17], [21, 19, -40, 21, -21, 0, 40, -21], [7, 0, -22, 22, 0, 0, 0, -22], [8, 1, -9, 8, -8, 0, 9, -8]];
    aps := ConvertToHeckeField(raw_aps);
    chi := MakeCharacter_99_m_Hecke( : Kf := Universe(aps));
    return ExtendMultiplicatively(weight, aps, chi);
end function;


// To make the newform (type ModFrm), type "MakeNewformModFrm_99_2_m_a();".
// 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_99_2_m_a(:prec:=8)
    chi := MakeCharacter_99_m();
    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_99_2_m_a();".
// 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_99_2_m_a( : sign := -1)
    R<x> := PolynomialRing(Rationals());
    chi := MakeCharacter_99_m();
    // SetVerbose("ModularSymbols", true);
    Snew := NewSubspace(CuspidalSubspace(ModularSymbols(chi,2,sign)));
    Vf := Kernel([<2,R![1, -1, -5, -14, 39, 26, 10, 4, 1]>],Snew);
    return Vf;
end function;