/* 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![5, -1, -6, 0, 1]; F := NumberField(g); ZF := Integers(F); NN := ideal; primesArray := [ [5, 5, w], [5, 5, -w^2 + w + 2], [7, 7, -w^2 + 2], [13, 13, -w^2 + 3], [13, 13, w^2 - w - 4], [16, 2, 2], [19, 19, -w^2 + w + 1], [23, 23, -w^3 + 4*w + 2], [25, 5, -w^3 + w^2 + 3*w - 1], [29, 29, w^3 - w^2 - 4*w + 1], [29, 29, -w + 3], [31, 31, -w^3 + w^2 + 5*w - 2], [37, 37, w^3 - 4*w - 1], [37, 37, w^3 - 3*w + 1], [53, 53, -w^3 + 2*w^2 + 4*w - 6], [59, 59, w^2 + w - 4], [61, 61, -2*w^2 + w + 8], [73, 73, -w^3 + 5*w - 1], [79, 79, 2*w^2 + w - 6], [79, 79, 2*w^3 - w^2 - 9*w + 3], [81, 3, -3], [83, 83, -w^3 + w^2 + 3*w - 4], [97, 97, -w^3 + 6*w + 2], [97, 97, -2*w^3 + w^2 + 10*w - 1], [97, 97, 3*w^3 - 4*w^2 - 15*w + 13], [97, 97, w^3 - w^2 - 6*w + 2], [103, 103, -2*w^3 + 3*w^2 + 11*w - 9], [109, 109, w^2 + 3*w - 3], [137, 137, -w^2 + 7], [149, 149, w^3 - 2*w^2 - 5*w + 4], [149, 149, w^3 + 2*w^2 - 6*w - 7], [151, 151, w^3 + w^2 - 5*w - 3], [163, 163, w^3 - 3*w - 4], [163, 163, -w^3 + 6*w - 3], [167, 167, w^3 - 2*w^2 - 6*w + 4], [169, 13, w^2 + 2*w - 4], [191, 191, w^3 - w^2 - 5*w - 2], [191, 191, 2*w^3 - 9*w - 2], [197, 197, w^3 - 4*w + 4], [211, 211, -w^3 + 2*w^2 + 6*w - 8], [223, 223, -w^3 + 3*w^2 + 4*w - 6], [229, 229, w^3 - w^2 - 5*w - 1], [251, 251, 2*w^3 - 2*w^2 - 7*w + 3], [257, 257, 3*w^2 - 14], [263, 263, w^2 - 3*w - 1], [263, 263, w^2 - 2*w - 7], [269, 269, -w^3 + w^2 + 2*w - 4], [269, 269, 2*w^3 - 11*w - 1], [271, 271, -w^3 + w^2 + 4*w - 7], [277, 277, w^3 - w^2 - 3*w + 8], [311, 311, w^3 + 2*w^2 - 7*w - 11], [311, 311, -3*w^2 - 2*w + 8], [317, 317, -2*w^3 + 2*w^2 + 7*w - 4], [331, 331, w^2 - w - 8], [331, 331, 3*w^3 - 2*w^2 - 12*w + 9], [337, 337, -2*w^3 + 2*w^2 + 11*w - 8], [343, 7, w^3 - 3*w^2 - 4*w + 11], [347, 347, -2*w^3 + 2*w^2 + 9*w - 4], [349, 349, -w^3 + 2*w^2 + 2*w - 6], [353, 353, 2*w^2 - w - 12], [353, 353, 2*w^3 - w^2 - 9*w - 1], [367, 367, -2*w^3 + w^2 + 10*w - 6], [367, 367, 2*w^3 - 11*w - 3], [379, 379, -3*w - 1], [379, 379, w^3 - 2*w - 3], [383, 383, -w^3 + 2*w^2 + 4*w - 11], [383, 383, -w^3 - w^2 + 7*w + 4], [389, 389, 2*w^3 - w^2 - 11*w + 4], [401, 401, w^3 + 2*w^2 - 7*w - 6], [401, 401, 2*w^3 - 11*w - 6], [419, 419, -2*w^3 + w^2 + 8*w - 1], [421, 421, -w^3 + 3*w^2 + 3*w - 12], [421, 421, -w^3 - 2*w^2 + 2*w + 6], [433, 433, w^3 - 2*w^2 - 6*w + 11], [433, 433, w^2 - 8], [439, 439, -w^3 + 3*w^2 + 3*w - 7], [443, 443, w^3 - w^2 - 2*w - 4], [443, 443, 2*w^3 + w^2 - 7*w - 2], [443, 443, 2*w^3 - w^2 - 8*w + 2], [443, 443, -w^2 - 2], [467, 467, 3*w^3 - 5*w^2 - 15*w + 19], [467, 467, 2*w^3 - 3*w^2 - 8*w + 13], [467, 467, -w^3 + 2*w^2 + 3*w - 9], [467, 467, -w^3 + 3*w^2 + 3*w - 8], [479, 479, -w^3 - 3*w^2 + 5*w + 13], [479, 479, -w^3 + w^2 + w - 4], [487, 487, 3*w^3 - w^2 - 13*w - 2], [491, 491, w^2 + w - 9], [499, 499, -3*w^3 + 3*w^2 + 13*w - 7], [503, 503, 2*w^2 + w - 9], [509, 509, -2*w^2 - 3*w + 6], [509, 509, -w^3 + w^2 - 4], [521, 521, -3*w^2 + w + 12], [523, 523, 2*w^3 - 8*w - 3], [529, 23, 2*w^3 - w^2 - 6*w - 1], [541, 541, -w^3 + w^2 + 7*w - 4], [547, 547, 2*w^3 - 3*w^2 - 9*w + 7], [557, 557, 3*w^2 - 2*w - 9], [557, 557, w^3 - 6*w - 7], [563, 563, -2*w^3 + w^2 + 6*w - 6], [577, 577, -w^3 + 4*w^2 + 2*w - 13], [587, 587, w^2 - 2*w + 3], [587, 587, w^2 + 2*w - 6], [593, 593, -2*w^3 + 2*w^2 + 11*w - 3], [599, 599, w^3 + 3*w^2 - 6*w - 12], [601, 601, -2*w^3 + w^2 + 9*w + 2], [607, 607, -w^3 + 3*w^2 + 4*w - 9], [617, 617, -2*w^3 + w^2 + 7*w - 3], [619, 619, -2*w^3 + 4*w^2 + 9*w - 11], [631, 631, 3*w^2 - w - 7], [631, 631, -w^3 - w^2 + 6*w + 1], [641, 641, -w^3 + 2*w^2 + 5*w - 1], [641, 641, -w^3 + 2*w^2 + 2*w - 7], [643, 643, -3*w^3 + w^2 + 14*w - 4], [647, 647, -3*w^3 + 5*w^2 + 14*w - 18], [647, 647, -w^3 + 7*w + 2], [647, 647, -2*w^3 + 7*w - 1], [647, 647, 2*w^3 - w^2 - 10*w - 1], [653, 653, -2*w^3 - w^2 + 11*w + 4], [659, 659, -w^3 - w^2 + 5*w - 1], [673, 673, -w^3 + w^2 + 7*w - 2], [673, 673, -w^3 + w^2 + 2*w - 8], [683, 683, 2*w^3 - 11*w - 8], [683, 683, 2*w^3 - 7*w - 3], [701, 701, 2*w^3 - 4*w^2 - 10*w + 17], [727, 727, -w^3 + w^2 + 4*w - 8], [727, 727, 3*w^2 - 11], [739, 739, 2*w^3 + 3*w^2 - 8*w - 13], [743, 743, 2*w^2 + w - 12], [743, 743, 3*w^2 - 2*w - 14], [751, 751, w^3 + w^2 - 3*w - 7], [757, 757, -2*w^3 + 10*w - 1], [761, 761, -2*w^3 + w^2 + 7*w - 1], [761, 761, 3*w^2 + w - 7], [773, 773, -2*w^3 + 2*w^2 + 8*w - 1], [797, 797, -2*w^3 + w^2 + 9*w + 3], [797, 797, 3*w^3 - 14*w - 8], [809, 809, 5*w^3 - 5*w^2 - 24*w + 16], [821, 821, -4*w^3 + 3*w^2 + 18*w - 9], [821, 821, w^3 - w - 3], [823, 823, 3*w^2 + w - 8], [829, 829, -2*w^3 + 3*w^2 + 10*w - 7], [829, 829, 3*w^2 - 2*w - 16], [841, 29, 2*w^2 + w - 11], [853, 853, 3*w^3 - 2*w^2 - 14*w + 3], [853, 853, 3*w^3 - 5*w^2 - 14*w + 17], [857, 857, 3*w^2 - w - 8], [857, 857, 3*w^3 - w^2 - 13*w + 3], [859, 859, w^3 - 3*w^2 - 6*w + 12], [877, 877, w^3 + 2*w^2 - 5*w - 4], [877, 877, w^2 - w - 9], [881, 881, w^3 + 2*w^2 - 4*w - 12], [881, 881, w^2 - 4*w - 4], [883, 883, -3*w^3 + 2*w^2 + 11*w - 8], [887, 887, -2*w^3 + w^2 + 6*w - 1], [911, 911, 3*w^2 - w - 17], [911, 911, 2*w^3 - 2*w^2 - 12*w + 3], [919, 919, 5*w^3 - 6*w^2 - 22*w + 24], [919, 919, -2*w^3 + w^2 + 6*w - 7], [929, 929, 2*w^3 - 7*w - 1], [937, 937, -w^3 - w^2 + 8*w - 2], [947, 947, 3*w^3 + w^2 - 15*w - 6], [947, 947, -2*w^3 + 9*w + 9], [953, 953, w^3 - 2*w^2 - 6*w + 1], [977, 977, w^3 - w^2 - 3*w + 9], [977, 977, w^3 + w^2 - 3*w - 8], [983, 983, w^3 - 5*w - 7], [991, 991, -w^3 + 2*w^2 + 2*w - 8], [991, 991, w^2 + 4*w - 1], [997, 997, 2*w^3 + w^2 - 12*w - 8]]; primes := [ideal : I in primesArray]; heckePol := x^4 - 7*x^2 + 8; K := NumberField(heckePol); heckeEigenvaluesArray := [e^2 - 3, 0, e, -e^3 + 5*e + 1, e^2 + 2*e - 5, e^3 + e^2 - 4*e - 3, -2*e^2 + e + 6, -2*e^2 + 2*e + 8, e^2 - e + 1, e^2 - 2*e - 2, e^3 + e^2 - 5*e - 3, -e^3 + 2*e^2 + 5*e - 4, e^2 - 4*e - 7, -e^3 + e^2 + 5*e - 1, -e^3 + e^2 + 3*e - 7, -e^3 + 2*e^2 + 5*e - 6, -e^3 + 2*e^2 + 4*e - 6, 2*e^3 - e^2 - 14*e + 1, -2*e^3 + 2*e^2 + 10*e + 2, -e^3 + e^2 + 3*e + 4, 2*e^3 + 3*e^2 - 8*e - 13, 3*e - 6, -3*e^3 - 3*e^2 + 11*e + 11, e^3 - e^2 - 3*e + 9, -3*e^3 - e^2 + 15*e + 1, 2*e^3 - 2*e^2 - 10*e + 6, 2*e^3 - 4*e + 2, e^2 - 1, -5*e^3 - e^2 + 21*e + 1, -6*e^2 - 2*e + 22, -e^3 + 11*e + 11, -4*e^3 + 22*e + 2, -2*e^3 - 4*e^2 + 8*e + 12, e^3 - 2*e^2 - 7*e - 8, -e^3 + 2*e^2 + 7*e - 14, -2*e^3 - 4*e^2 + 8*e + 21, 3*e^3 + e^2 - 19*e - 2, -3*e^3 - 6*e^2 + 17*e + 20, 2*e^2 + 8*e - 15, e^3 - 2*e^2 + e + 12, 2*e^3 - 4*e^2 - 14*e + 18, 2*e^3 + 2*e^2 - 10*e - 3, -e^3 - 3*e^2 + 7*e - 6, -2*e^3 - e^2 + 12*e + 7, e^3 - 2*e^2 - 9*e + 14, 4*e^3 + 4*e^2 - 23*e - 14, 4*e^3 + e^2 - 14*e - 3, -e^3 - 9*e^2 + 3*e + 35, 6*e - 6, 2*e^3 - 2*e^2 - 12*e + 11, -3*e^3 + e^2 + 9*e - 4, -2*e^3 + 2*e^2 + 3*e - 10, -4*e^3 + 3*e^2 + 14*e - 10, e^3 + 6*e^2 - 15*e - 22, -4*e^3 - 2*e^2 + 18*e - 4, -e^3 + e^2 + 3*e - 3, 2*e^3 + 4*e^2 - 8*e - 16, 3*e^3 + 4*e^2 - 14*e + 4, 3*e^3 + 6*e^2 - 20*e - 22, -2*e^3 - 2*e^2 + 10*e - 2, -4*e^3 - 4*e^2 + 18*e + 18, -3*e^3 - 4*e^2 + 13*e + 8, -6*e^3 + 4*e^2 + 21*e - 18, -2*e^3 + 3*e^2 + 12*e - 18, -5*e^3 - 6*e^2 + 27*e + 22, e^3 - 4*e^2 + 4*e + 22, 6*e^3 + 6*e^2 - 28*e - 22, 6*e^2 - 38, e^3 - 5*e^2 - 16*e + 23, -5*e^3 + 5*e^2 + 25*e - 11, 5*e^3 - e^2 - 33*e + 6, 2*e^3 - 12*e^2 - 10*e + 38, 3*e^3 - e^2 - 7*e + 15, -3*e^3 - 5*e^2 + 5*e + 29, e^3 - 4*e^2 - e + 11, -2*e^3 - 10*e^2 + 8*e + 36, -4*e^3 - e^2 + 12*e + 18, -4*e^3 - 2*e^2 + 18*e + 12, 8*e^3 + 2*e^2 - 38*e, 7*e^3 - 29*e + 4, 2*e^3 + 2*e^2 - 13*e + 8, -e^3 - 9*e^2 - e + 36, 2*e^3 + 2*e^2 - 10*e + 18, -3*e^3 + 6*e^2 + 12*e - 16, e^3 - 2*e^2 - 11*e - 14, -e^3 - e^2 - e + 20, 2*e^3 - 8*e - 2, 5*e^3 - 2*e^2 - 23*e + 14, 5*e^3 - e^2 - 17*e + 12, -10*e^3 + 6*e^2 + 48*e - 10, -5*e^2 - e + 11, -3*e^3 - e^2 + 7*e + 11, -e^3 + 7*e^2 + 14*e - 19, 5*e^3 - 7*e^2 - 17*e + 26, -2*e^3 - 11*e^2 + 10*e + 31, -3*e^3 + 16*e + 2, -4*e^3 + 6*e^2 + 16*e - 20, -2*e^3 + 5*e^2 - 2*e - 14, 3*e^3 + e^2 - 19*e + 5, -3*e^3 - 5*e^2 + 17*e + 38, 6*e^3 - 8*e^2 - 22*e + 26, 8*e^3 - 4*e^2 - 38*e + 12, -2*e^3 - 8*e^2 + 16*e + 16, -e^3 + 7*e^2 + 14*e - 33, -3*e^3 + 29*e + 12, 2*e^2 + 6*e + 14, -3*e^3 + 4*e^2 + 22*e, -3*e^3 + 13*e^2 + 9*e - 55, -2*e^3 - 4*e^2 + 6*e - 8, 2*e^3 - 24*e, 8*e^3 + 4*e^2 - 32*e - 26, 2*e^3 + 5*e^2 - 11*e + 9, 3*e^3 - 9*e^2 - 9*e + 51, e^3 + 8*e^2 - 11*e - 20, 10*e^3 - e^2 - 36*e + 6, 6*e^3 - e^2 - 38*e + 2, 2*e^3 - 12*e^2 - 4*e + 48, 18*e^2 + 3*e - 68, e^3 - 11*e^2 - 11*e + 45, 5*e^3 + e^2 - 19*e - 24, -8*e^3 + 4*e^2 + 32*e - 18, 2*e^3 + e^2 - 11*e + 19, 4*e^3 - 16*e + 22, -2*e^3 + 8*e^2 + 3*e - 30, 4*e^3 - 5*e^2 - 16*e + 23, 4*e^3 + 8*e^2 - 18*e - 24, -e^3 + 6*e^2 + 3*e + 2, -e^3 + 8*e^2 + 11*e - 40, 2*e^3 + 2*e - 14, -6*e^3 - 6*e^2 + 30*e + 28, -8*e^2 - 12*e + 28, 2*e^3 + 3*e^2 - 28*e - 14, -4*e^3 - 3*e^2 + 20*e + 19, 7*e^3 - 7*e^2 - 45*e + 5, -3*e^2 - 6*e + 31, -4*e^3 + 13*e^2 + 20*e - 43, 4*e^3 + 10*e^2 - 32*e - 26, -e^3 - 3*e^2 - e + 33, -2*e^3 - 13*e^2 + 51, -5*e^3 + 5*e^2 + 24*e - 25, -4*e^2 - 8*e + 28, -7*e^3 + 10*e^2 + 38*e - 14, 3*e^3 + 9*e^2 - 13*e - 19, -2*e^3 + 5*e^2 + 26*e - 13, -2*e^3 + 9*e^2 + 16*e - 11, 2*e^3 - 8*e^2 + 2*e + 30, -7*e^3 - e^2 + 34*e + 13, 8*e^3 - 6*e^2 - 32*e + 31, 2*e^3 - 6*e^2 + 46, e^3 - 4*e^2 + 5*e - 1, -3*e^3 + e^2 + 25*e + 1, 6*e^3 - 2*e^2 - 36*e - 7, -4*e^2 + 6, e^3 - 12*e^2 + 5*e + 42, e^3 + 2*e^2 - 17*e - 8, -2*e^3 - 2*e^2 + 15*e + 16, 3*e^2 + 18*e - 18, -2*e^3 - 6*e^2 + 18*e + 40, -3*e^3 + 13*e + 12, -3*e^2 - 9*e + 7, 2*e^3 + 14*e^2 - 4*e - 46, -2*e^3 - 9*e^2 + 10*e + 18, 3*e^3 - 2*e^2 - 13*e + 26, -11*e^3 + 5*e^2 + 39*e - 29, -3*e^3 - 11*e^2 + 7*e + 31, -8*e^3 - 7*e^2 + 46*e + 21, -4*e + 12, 4*e^3 + 8*e^2 - 24*e - 46, -6*e^3 + 2*e^2 + 17*e - 16, 6*e^3 - e^2 - 26*e - 18]; 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;