/* This code can be loaded, or copied and pasted, into Magma. It will load the data associated to the HMF, including the field, level, and Hecke and Atkin-Lehner eigenvalue data. At the *bottom* of the file, there is code to recreate the Hilbert modular form in Magma, by creating the HMF space and cutting out the corresponding Hecke irreducible subspace. From there, you can ask for more eigenvalues or modify as desired. It is commented out, as this computation may be lengthy. */ P := PolynomialRing(Rationals()); g := P![-1, -2, 5, 4, -5, -1, 1]; F := NumberField(g); ZF := Integers(F); NN := ideal; primesArray := [ [7, 7, w^5 - 5*w^3 + 4*w], [13, 13, -w^3 + 3*w], [25, 5, w^4 - w^3 - 4*w^2 + 2*w + 2], [31, 31, -w^5 + 5*w^3 - 5*w + 1], [31, 31, -w^4 + w^3 + 5*w^2 - 3*w - 3], [37, 37, w^4 - 5*w^2 + w + 3], [43, 43, -2*w^5 + w^4 + 9*w^3 - 3*w^2 - 6*w], [47, 47, w^5 - w^4 - 4*w^3 + 4*w^2 - 2], [49, 7, -w^4 + 4*w^2 + w - 3], [53, 53, -w^4 + w^3 + 4*w^2 - 3*w - 4], [59, 59, w^4 - 5*w^2 - w + 5], [61, 61, w^3 - w^2 - 3*w], [64, 2, -2], [67, 67, -2*w^5 + w^4 + 9*w^3 - 3*w^2 - 7*w], [67, 67, 2*w^5 - w^4 - 10*w^3 + 4*w^2 + 9*w - 1], [73, 73, w^5 - w^4 - 4*w^3 + 5*w^2 + w - 3], [73, 73, 3*w^5 - 3*w^4 - 13*w^3 + 11*w^2 + 7*w - 3], [83, 83, -2*w^5 + 3*w^4 + 9*w^3 - 11*w^2 - 6*w + 2], [97, 97, -2*w^4 + w^3 + 9*w^2 - 3*w - 4], [101, 101, -2*w^5 + 3*w^4 + 9*w^3 - 11*w^2 - 6*w + 4], [101, 101, w^5 - 2*w^4 - 4*w^3 + 9*w^2 + w - 4], [107, 107, -2*w^5 + w^4 + 10*w^3 - 4*w^2 - 9*w + 2], [107, 107, -w^5 + w^4 + 6*w^3 - 4*w^2 - 8*w + 2], [113, 113, w^5 - w^4 - 4*w^3 + 3*w^2 + 2*w + 2], [121, 11, w^5 - w^4 - 5*w^3 + 3*w^2 + 5*w - 2], [127, 127, 2*w^5 - 3*w^4 - 9*w^3 + 12*w^2 + 5*w - 4], [131, 131, w^5 - w^4 - 6*w^3 + 4*w^2 + 8*w - 1], [131, 131, 2*w^5 - 3*w^4 - 7*w^3 + 12*w^2 - w - 4], [149, 149, -2*w^5 + 2*w^4 + 8*w^3 - 8*w^2 - 3*w + 4], [151, 151, w^5 - 2*w^4 - 4*w^3 + 8*w^2 + 3*w - 3], [157, 157, w^5 - w^4 - 4*w^3 + 5*w^2 - w - 2], [163, 163, -2*w^5 + 2*w^4 + 9*w^3 - 6*w^2 - 6*w], [163, 163, w^5 - 2*w^4 - 4*w^3 + 8*w^2 - 4], [163, 163, -2*w^5 + w^4 + 9*w^3 - 4*w^2 - 7*w + 4], [173, 173, 2*w^4 - w^3 - 8*w^2 + 2*w + 4], [173, 173, -w^5 + 3*w^4 + 4*w^3 - 14*w^2 - w + 9], [179, 179, -w^5 + 2*w^4 + 4*w^3 - 8*w^2 + 6], [191, 191, 2*w^4 - 2*w^3 - 9*w^2 + 6*w + 5], [193, 193, -w^5 + w^4 + 5*w^3 - 4*w^2 - 6*w + 2], [199, 199, -2*w^5 + 3*w^4 + 9*w^3 - 11*w^2 - 6*w + 3], [211, 211, -w^5 + 5*w^3 - 2*w - 2], [211, 211, -2*w^5 + w^4 + 9*w^3 - 4*w^2 - 5*w + 1], [211, 211, w^5 - 5*w^3 - 2*w^2 + 4*w + 4], [223, 223, w^5 - 5*w^3 - w^2 + 7*w + 1], [227, 227, -w^5 + w^4 + 6*w^3 - 4*w^2 - 7*w + 1], [227, 227, w^3 - 2*w^2 - 4*w + 3], [229, 229, -w^5 + 6*w^3 - 7*w + 1], [233, 233, 3*w^5 - 2*w^4 - 15*w^3 + 8*w^2 + 13*w - 3], [233, 233, -w^5 + 4*w^3 + w^2 - 2*w - 3], [233, 233, -w^3 + w^2 + 4*w - 1], [257, 257, w^5 - 2*w^4 - 5*w^3 + 8*w^2 + 4*w - 2], [257, 257, w^5 + w^4 - 6*w^3 - 4*w^2 + 6*w + 1], [263, 263, 3*w^5 - 3*w^4 - 13*w^3 + 10*w^2 + 7*w - 1], [269, 269, w^5 - w^4 - 4*w^3 + 5*w^2 - 3], [283, 283, w^5 - w^4 - 5*w^3 + 5*w^2 + 5*w - 1], [293, 293, -2*w^4 + w^3 + 8*w^2 - 3*w - 4], [293, 293, 2*w^5 - 4*w^4 - 8*w^3 + 17*w^2 + 3*w - 8], [307, 307, w^5 - 7*w^3 + 11*w - 1], [311, 311, w^4 - 2*w^3 - 4*w^2 + 8*w + 1], [313, 313, -w^5 + 5*w^3 + w^2 - 3*w - 3], [317, 317, -w^5 + 4*w^3 - w^2 - w + 4], [317, 317, -3*w^5 + 4*w^4 + 13*w^3 - 16*w^2 - 6*w + 8], [331, 331, w^5 - 7*w^3 + 10*w], [331, 331, 3*w^4 - 2*w^3 - 13*w^2 + 7*w + 7], [331, 331, w^5 - 4*w^3 + w^2 + w - 3], [343, 7, -4*w^5 + 3*w^4 + 19*w^3 - 10*w^2 - 15*w + 2], [347, 347, 2*w^5 - 2*w^4 - 10*w^3 + 7*w^2 + 7*w], [349, 349, 3*w^5 - 2*w^4 - 14*w^3 + 7*w^2 + 9*w + 1], [349, 349, -w^5 + 2*w^4 + 3*w^3 - 9*w^2 + w + 7], [359, 359, 2*w^5 - 2*w^4 - 10*w^3 + 7*w^2 + 10*w - 4], [359, 359, w^5 - 7*w^3 + 11*w + 1], [373, 373, w^5 - 6*w^3 + 6*w - 2], [383, 383, -4*w^5 + 4*w^4 + 18*w^3 - 14*w^2 - 12*w + 3], [389, 389, w^5 + w^4 - 5*w^3 - 5*w^2 + 6*w + 4], [397, 397, 2*w^5 - w^4 - 9*w^3 + 5*w^2 + 6*w - 5], [397, 397, -2*w^5 + 3*w^4 + 8*w^3 - 10*w^2 - 3*w + 3], [409, 409, -w^5 + w^4 + 5*w^3 - 3*w^2 - 6*w - 3], [421, 421, -3*w^5 + w^4 + 14*w^3 - 3*w^2 - 10*w - 2], [431, 431, 2*w^4 - w^3 - 10*w^2 + 3*w + 7], [433, 433, -3*w^5 + 2*w^4 + 14*w^3 - 6*w^2 - 11*w + 2], [433, 433, 2*w^5 - 3*w^4 - 10*w^3 + 11*w^2 + 10*w - 2], [439, 439, -2*w^5 + 2*w^4 + 10*w^3 - 8*w^2 - 7*w + 3], [439, 439, 3*w^5 - 4*w^4 - 13*w^3 + 16*w^2 + 8*w - 5], [439, 439, -w^5 + w^4 + 5*w^3 - 6*w^2 - 4*w + 6], [461, 461, w^5 + w^4 - 5*w^3 - 4*w^2 + 6*w + 1], [467, 467, w^5 + w^4 - 4*w^3 - 6*w^2 + w + 5], [479, 479, w^5 - w^4 - 5*w^3 + 3*w^2 + 2*w + 1], [487, 487, 3*w^5 - 3*w^4 - 13*w^3 + 12*w^2 + 7*w - 3], [499, 499, 2*w^5 - 2*w^4 - 11*w^3 + 7*w^2 + 12*w - 1], [503, 503, w^5 - 2*w^4 - 5*w^3 + 9*w^2 + 5*w - 3], [509, 509, 3*w^5 - 3*w^4 - 15*w^3 + 11*w^2 + 13*w - 2], [509, 509, 2*w^5 - 2*w^4 - 10*w^3 + 7*w^2 + 11*w - 2], [521, 521, 3*w^5 - 3*w^4 - 14*w^3 + 10*w^2 + 11*w - 3], [521, 521, -w^5 + 2*w^4 + 5*w^3 - 6*w^2 - 5*w], [523, 523, -2*w^5 + 2*w^4 + 10*w^3 - 7*w^2 - 11*w + 1], [523, 523, -2*w^5 + w^4 + 10*w^3 - 3*w^2 - 11*w], [523, 523, -2*w^5 + w^4 + 10*w^3 - 4*w^2 - 10*w + 4], [547, 547, -2*w^4 + 2*w^3 + 10*w^2 - 6*w - 7], [557, 557, 3*w^5 - 3*w^4 - 14*w^3 + 10*w^2 + 9*w - 1], [569, 569, 3*w^5 - 4*w^4 - 13*w^3 + 14*w^2 + 8*w - 2], [571, 571, w^4 + w^3 - 5*w^2 - 2*w + 5], [577, 577, 3*w^4 - 2*w^3 - 13*w^2 + 7*w + 6], [577, 577, w^5 + w^4 - 5*w^3 - 4*w^2 + 4*w + 4], [587, 587, 2*w^5 - w^4 - 10*w^3 + 5*w^2 + 9*w - 4], [599, 599, -2*w^5 + 3*w^4 + 10*w^3 - 12*w^2 - 9*w + 3], [599, 599, w^5 + 2*w^4 - 6*w^3 - 9*w^2 + 8*w + 6], [601, 601, -2*w^5 + 3*w^4 + 8*w^3 - 11*w^2 - 5*w + 4], [607, 607, w^5 - 2*w^4 - 5*w^3 + 8*w^2 + 3*w - 1], [613, 613, w^5 - 2*w^4 - 5*w^3 + 10*w^2 + 5*w - 7], [613, 613, -w^5 + 2*w^4 + 3*w^3 - 7*w^2], [617, 617, -3*w^5 + 3*w^4 + 12*w^3 - 11*w^2 - 5*w + 4], [625, 5, -2*w^5 + 2*w^4 + 9*w^3 - 6*w^2 - 5*w + 1], [631, 631, -2*w^5 + w^4 + 9*w^3 - 3*w^2 - 8*w + 1], [641, 641, w^5 - 5*w^3 - w^2 + 5*w + 5], [659, 659, -w^5 + 3*w^4 + 5*w^3 - 12*w^2 - 5*w + 3], [661, 661, 4*w^5 - 3*w^4 - 19*w^3 + 11*w^2 + 14*w - 2], [677, 677, -2*w^5 + 2*w^4 + 9*w^3 - 7*w^2 - 6*w - 2], [683, 683, -w^5 + w^4 + 4*w^3 - 5*w^2 + w + 4], [683, 683, -2*w^4 + w^3 + 9*w^2 - 5*w - 4], [701, 701, -2*w^5 + 3*w^4 + 10*w^3 - 11*w^2 - 10*w + 4], [701, 701, -3*w^5 + w^4 + 15*w^3 - 3*w^2 - 14*w + 1], [709, 709, 2*w^4 - 2*w^3 - 9*w^2 + 5*w + 7], [719, 719, w^4 - 2*w^3 - 4*w^2 + 7*w + 4], [719, 719, w^3 + 2*w^2 - 4*w - 5], [727, 727, 2*w^5 - 3*w^4 - 8*w^3 + 11*w^2 + 4*w - 1], [729, 3, -3], [743, 743, 3*w^5 - 2*w^4 - 15*w^3 + 6*w^2 + 12*w], [743, 743, -w^4 + w^3 + 6*w^2 - 4*w - 3], [769, 769, 2*w^5 - 3*w^4 - 8*w^3 + 12*w^2 + 3*w - 2], [769, 769, -3*w^5 + 4*w^4 + 13*w^3 - 15*w^2 - 8*w + 3], [787, 787, 2*w^3 - w^2 - 5*w], [797, 797, 3*w^5 - w^4 - 15*w^3 + 4*w^2 + 12*w - 1], [827, 827, 3*w^4 - w^3 - 13*w^2 + 2*w + 8], [839, 839, -2*w^5 + w^4 + 10*w^3 - 4*w^2 - 11*w + 2], [853, 853, -2*w^4 + w^3 + 10*w^2 - 4*w - 6], [853, 853, -w^5 + w^4 + 6*w^3 - 3*w^2 - 7*w - 3], [853, 853, -2*w^5 + 3*w^4 + 9*w^3 - 11*w^2 - 8*w + 3], [857, 857, w^5 - 2*w^4 - 3*w^3 + 10*w^2 - 2*w - 7], [859, 859, -4*w^5 + 3*w^4 + 18*w^3 - 10*w^2 - 12*w], [863, 863, w^5 - 3*w^4 - 3*w^3 + 14*w^2 - 2*w - 9], [877, 877, -w^5 + 7*w^3 - 12*w - 1], [881, 881, 2*w^4 - 2*w^3 - 9*w^2 + 8*w + 6], [881, 881, 3*w^5 - w^4 - 15*w^3 + 4*w^2 + 12*w - 2], [887, 887, -w^5 - w^4 + 5*w^3 + 5*w^2 - 2*w - 4], [919, 919, 4*w^5 - 4*w^4 - 18*w^3 + 14*w^2 + 11*w - 3], [919, 919, -w^5 + 4*w^3 - w - 3], [929, 929, -w^5 + 2*w^4 + 4*w^3 - 10*w^2 + 5], [937, 937, 3*w^5 - 4*w^4 - 12*w^3 + 15*w^2 + 5*w - 3], [947, 947, 3*w^5 - 3*w^4 - 13*w^3 + 10*w^2 + 8*w - 4], [953, 953, 2*w^5 - 9*w^3 - w^2 + 6*w + 4], [953, 953, -3*w^5 + 3*w^4 + 12*w^3 - 11*w^2 - 5*w + 2], [967, 967, -2*w^5 + 9*w^3 + 2*w^2 - 7*w - 4], [977, 977, 3*w^5 - w^4 - 14*w^3 + 3*w^2 + 11*w - 1], [977, 977, w^4 - w^3 - 6*w^2 + 3*w + 3], [997, 997, 3*w^5 - 2*w^4 - 15*w^3 + 7*w^2 + 13*w - 4]]; primes := [ideal : I in primesArray]; heckePol := x; K := Rationals(); e := 1; heckeEigenvaluesArray := [-3, 1, 3, -10, -7, -5, -8, -1, -6, 6, -4, -9, -13, 10, -2, 0, -12, -3, -4, 15, -12, -10, -10, 0, -8, -5, -2, 16, 4, -10, 4, -8, 3, -13, -9, 8, 2, -6, 5, 24, 20, -4, 16, 22, 9, -16, 19, -18, 6, 3, -14, 14, -23, -22, -4, -24, 14, -16, -11, 26, -10, 18, 1, 6, -17, 6, 0, 29, -8, 20, 25, 14, 24, -24, -27, -22, -10, 38, -7, -30, -16, -13, -16, 38, -15, 23, -39, -28, 19, 10, 4, -5, 9, 3, -27, -11, 20, 23, 24, 24, -15, 18, 16, 15, 29, 11, -20, 43, -22, -47, 18, -8, 7, 8, 34, -28, 6, 20, -36, -7, 3, -1, -20, -27, -48, -4, 36, 18, -21, -30, 12, -22, 0, 34, -30, -35, 46, 17, 36, -28, -18, 6, 22, -36, -15, -21, 49, 12, 3, -9, -51, -4, -15, -28, 46]; heckeEigenvalues := AssociativeArray(); for i := 1 to #heckeEigenvaluesArray do heckeEigenvalues[primes[i]] := heckeEigenvaluesArray[i]; end for; ALEigenvalues := AssociativeArray(); ALEigenvalues[ideal] := -1; // EXAMPLE: // pp := Factorization(2*ZF)[1][1]; // heckeEigenvalues[pp]; print "To reconstruct the Hilbert newform f, type f, iso := Explode(make_newform());"; function make_newform(); M := HilbertCuspForms(F, NN); S := NewSubspace(M); // SetVerbose("ModFrmHil", 1); NFD := NewformDecomposition(S); newforms := [* Eigenform(U) : U in NFD *]; if #newforms eq 0 then; print "No Hilbert newforms at this level"; return 0; end if; print "Testing ", #newforms, " possible newforms"; newforms := [* f: f in newforms | IsIsomorphic(BaseField(f), K) *]; print #newforms, " newforms have the correct Hecke field"; if #newforms eq 0 then; print "No Hilbert newform found with the correct Hecke field"; return 0; end if; autos := Automorphisms(K); xnewforms := [* *]; for f in newforms do; if K eq RationalField() then; Append(~xnewforms, [* f, autos[1] *]); else; flag, iso := IsIsomorphic(K,BaseField(f)); for a in autos do; Append(~xnewforms, [* f, a*iso *]); end for; end if; end for; newforms := xnewforms; for P in primes do; xnewforms := [* *]; for f_iso in newforms do; f, iso := Explode(f_iso); if HeckeEigenvalue(f,P) eq iso(heckeEigenvalues[P]) then; Append(~xnewforms, f_iso); end if; end for; newforms := xnewforms; if #newforms eq 0 then; print "No Hilbert newform found which matches the Hecke eigenvalues"; return 0; else if #newforms eq 1 then; print "success: unique match"; return newforms[1]; end if; end if; end for; print #newforms, "Hilbert newforms found which match the Hecke eigenvalues"; return newforms[1]; end function;