/* 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![3, -4, -8, -1, 1]; F := NumberField(g); ZF := Integers(F); NN := ideal; primesArray := [ [3, 3, w], [3, 3, w^3 - 2*w^2 - 6*w + 1], [9, 3, w^3 - 2*w^2 - 5*w + 1], [16, 2, 2], [17, 17, w^3 - w^2 - 8*w - 5], [17, 17, -2*w^3 + 4*w^2 + 11*w - 2], [17, 17, -w^3 + 3*w^2 + 2*w - 2], [17, 17, w^3 - 2*w^2 - 4*w + 1], [25, 5, w^3 - 3*w^2 - 3*w + 1], [25, 5, w^2 - 2*w - 7], [29, 29, w^3 - 2*w^2 - 6*w - 1], [29, 29, w - 2], [53, 53, w^3 - 3*w^2 - 4*w + 4], [53, 53, -w^3 + 3*w^2 + 4*w - 5], [61, 61, -w^3 + 2*w^2 + 7*w - 4], [61, 61, -4*w^3 + 11*w^2 + 14*w - 8], [101, 101, -w^3 + 2*w^2 + 7*w - 1], [103, 103, -w^3 + 3*w^2 + 2*w - 5], [103, 103, -w^3 + w^2 + 8*w + 2], [113, 113, w^3 - 3*w^2 - 3*w + 7], [113, 113, w^2 - 2*w - 1], [127, 127, w^3 - 2*w^2 - 4*w - 2], [127, 127, -2*w^3 + 4*w^2 + 11*w + 1], [131, 131, -3*w^3 + 7*w^2 + 14*w - 8], [131, 131, -w^2 + w + 8], [131, 131, 2*w^3 - 5*w^2 - 9*w + 1], [131, 131, -3*w^3 + 6*w^2 + 16*w + 1], [139, 139, -2*w^3 + 5*w^2 + 9*w - 2], [139, 139, -w^2 + w + 7], [157, 157, -2*w^3 + 5*w^2 + 7*w - 5], [157, 157, -2*w^3 + 3*w^2 + 13*w + 2], [157, 157, -2*w^3 + 5*w^2 + 6*w - 2], [157, 157, -3*w^3 + 5*w^2 + 19*w + 4], [169, 13, -2*w^3 + 4*w^2 + 10*w - 1], [173, 173, 3*w^3 - 8*w^2 - 10*w + 7], [173, 173, 2*w^3 - 2*w^2 - 15*w - 8], [179, 179, -3*w^2 + 6*w + 17], [179, 179, -2*w^3 + 3*w^2 + 12*w + 1], [179, 179, -3*w^3 + 7*w^2 + 13*w - 7], [179, 179, -2*w^3 + 3*w^2 + 14*w + 4], [191, 191, w^3 - 3*w^2 - w + 4], [191, 191, -2*w^3 + 3*w^2 + 14*w + 2], [199, 199, -w^3 + 8*w + 10], [199, 199, 5*w^3 - 15*w^2 - 14*w + 14], [211, 211, -w - 4], [211, 211, -w^3 + 2*w^2 + 6*w - 5], [211, 211, 2*w^3 - 3*w^2 - 12*w - 4], [211, 211, -3*w^3 + 7*w^2 + 13*w - 4], [257, 257, -3*w^3 + 8*w^2 + 10*w - 2], [257, 257, 2*w^3 - 2*w^2 - 16*w - 7], [263, 263, 3*w^3 - 6*w^2 - 17*w + 1], [263, 263, w^3 - 2*w^2 - 3*w - 1], [269, 269, 5*w^3 - 13*w^2 - 19*w + 7], [269, 269, -3*w^3 + 6*w^2 + 18*w - 1], [277, 277, w^3 - 4*w^2 - w + 5], [277, 277, -w^3 + 4*w^2 + w - 11], [283, 283, -w^3 + 5*w^2 - w - 14], [283, 283, 2*w^3 - 7*w^2 - 4*w + 10], [283, 283, -w^3 + w^2 + 9*w + 1], [283, 283, w^2 - 4*w - 5], [311, 311, -w^3 + w^2 + 9*w + 5], [311, 311, w^2 - 4*w - 1], [313, 313, -4*w^3 + 9*w^2 + 19*w - 10], [313, 313, -2*w^2 + 5*w + 11], [337, 337, -3*w^3 + 6*w^2 + 14*w + 2], [337, 337, -4*w^3 + 8*w^2 + 21*w + 1], [347, 347, -2*w^3 + 6*w^2 + 7*w - 10], [347, 347, -w^3 + 4*w^2 + 2*w - 7], [361, 19, -4*w^3 + 11*w^2 + 13*w - 10], [361, 19, -2*w^3 + 5*w^2 + 8*w - 10], [373, 373, 2*w^3 - 5*w^2 - 10*w + 2], [373, 373, -w^3 + 2*w^2 + 8*w - 2], [373, 373, -2*w^3 + 4*w^2 + 13*w - 1], [373, 373, -w^3 + 3*w^2 + 5*w - 8], [389, 389, -w^3 + 4*w^2 + 2*w - 10], [389, 389, -2*w^3 + 6*w^2 + 7*w - 7], [419, 419, -2*w^3 + 5*w^2 + 6*w - 1], [419, 419, -3*w^3 + 5*w^2 + 19*w + 5], [433, 433, w^2 - 4*w - 2], [433, 433, w^3 - w^2 - 9*w - 4], [439, 439, -w^3 + 4*w^2 + w - 2], [439, 439, w^3 - 4*w^2 - w + 14], [443, 443, -2*w^3 + 5*w^2 + 9*w + 1], [443, 443, -w^2 + w + 10], [467, 467, w^3 - w^2 - 8*w + 4], [467, 467, w^3 - 4*w^2 + 2], [491, 491, -4*w^3 + 12*w^2 + 10*w - 11], [491, 491, 2*w^3 - w^2 - 18*w - 11], [491, 491, 3*w^3 - 9*w^2 - 7*w + 11], [491, 491, 2*w^3 - 20*w - 19], [503, 503, w^3 - 3*w^2 - 4*w + 10], [503, 503, -w^3 + w^2 + 10*w - 2], [523, 523, -4*w^3 + 9*w^2 + 22*w - 7], [523, 523, w^3 - 3*w^2 - 7*w + 5], [529, 23, -2*w^3 + 4*w^2 + 10*w + 5], [529, 23, -2*w^3 + 4*w^2 + 10*w - 7], [547, 547, 2*w^3 - w^2 - 18*w - 14], [547, 547, 3*w^3 - 8*w^2 - 14*w + 8], [571, 571, 5*w^3 - 11*w^2 - 25*w + 5], [571, 571, -4*w^3 + 9*w^2 + 19*w - 11], [599, 599, -5*w^3 + 12*w^2 + 20*w - 4], [599, 599, 4*w^3 - 6*w^2 - 25*w - 11], [601, 601, -4*w^3 + 9*w^2 + 20*w - 5], [601, 601, w^3 - 9*w - 14], [601, 601, 3*w^3 - 8*w^2 - 11*w + 2], [601, 601, -2*w^3 + 3*w^2 + 14*w - 1], [641, 641, -2*w^3 + 3*w^2 + 15*w - 5], [641, 641, -4*w^3 + 8*w^2 + 23*w - 2], [647, 647, -3*w^3 + 8*w^2 + 13*w - 11], [647, 647, -w^3 + 4*w^2 + 3*w - 7], [659, 659, 3*w^3 - 7*w^2 - 14*w - 2], [659, 659, w^3 - w^2 - 6*w - 11], [673, 673, -3*w^3 + 7*w^2 + 11*w - 1], [673, 673, -4*w^3 + 7*w^2 + 24*w + 5], [677, 677, 5*w^3 - 12*w^2 - 21*w + 11], [677, 677, -2*w^3 + 6*w^2 + 5*w - 1], [677, 677, -2*w^3 + 6*w^2 + 8*w - 7], [677, 677, 2*w^3 - 6*w^2 - 8*w + 11], [719, 719, -2*w^3 + 6*w^2 + 10*w - 7], [719, 719, -4*w^3 + 10*w^2 + 20*w - 13], [727, 727, 3*w^3 - 10*w^2 - 8*w + 10], [727, 727, 3*w^3 - 8*w^2 - 13*w + 10], [727, 727, 2*w^3 - 8*w^2 - 3*w + 23], [727, 727, -w^3 + 4*w^2 + 3*w - 8], [751, 751, -7*w^3 + 18*w^2 + 25*w - 7], [751, 751, w^3 - 7*w^2 + 5*w + 26], [757, 757, -4*w^3 + 9*w^2 + 18*w - 7], [757, 757, -3*w^3 + 5*w^2 + 17*w + 1], [797, 797, 2*w^2 - 4*w - 5], [797, 797, 2*w^3 - 6*w^2 - 6*w + 11], [823, 823, -2*w^3 + 2*w^2 + 15*w + 14], [823, 823, -3*w^3 + 8*w^2 + 10*w - 1], [829, 829, -6*w^3 + 16*w^2 + 22*w - 7], [829, 829, 5*w^3 - 13*w^2 - 20*w + 8], [829, 829, -w^3 + 7*w + 4], [829, 829, -5*w^3 + 12*w^2 + 23*w - 14], [841, 29, -3*w^3 + 6*w^2 + 15*w - 2], [859, 859, -4*w^3 + 7*w^2 + 24*w - 1], [859, 859, -5*w^3 + 15*w^2 + 14*w - 13], [881, 881, 3*w^3 - 7*w^2 - 16*w + 4], [881, 881, -w^3 + 3*w^2 + 6*w - 7], [883, 883, -2*w^3 + 3*w^2 + 12*w + 10], [883, 883, -3*w^3 + 7*w^2 + 13*w + 2], [887, 887, 4*w^3 - 11*w^2 - 11*w + 11], [887, 887, 2*w^3 - 7*w^2 - 3*w + 7], [887, 887, 4*w^3 - 5*w^2 - 29*w - 10], [887, 887, 3*w^2 - 7*w - 16], [907, 907, -w^3 + 3*w^2 + 8*w - 5], [907, 907, -5*w^3 + 11*w^2 + 28*w - 8], [911, 911, -4*w^3 + 10*w^2 + 18*w - 17], [911, 911, 2*w^2 - 2*w - 1], [919, 919, 4*w^3 - 7*w^2 - 25*w - 4], [919, 919, 2*w^3 - 5*w^2 - 5*w + 1], [937, 937, -w^3 + 3*w^2 + w - 8], [937, 937, -2*w^3 + 3*w^2 + 14*w - 2], [953, 953, -2*w^3 + w^2 + 17*w + 19], [953, 953, 4*w^3 - 11*w^2 - 13*w + 4], [961, 31, 2*w^3 - 3*w^2 - 11*w - 8], [961, 31, w^3 - 4*w^2 + 2*w + 11], [971, 971, 2*w^2 - 5*w - 4], [971, 971, -w^3 + 4*w^2 - 11], [991, 991, -2*w^3 + 6*w^2 + 9*w - 8], [991, 991, -2*w^3 + 3*w^2 + 13*w - 1], [991, 991, 3*w^3 - 8*w^2 - 14*w + 11], [991, 991, -2*w^3 + 5*w^2 + 7*w - 8], [997, 997, -2*w^3 + 5*w^2 + 6*w + 1], [997, 997, -3*w^3 + 5*w^2 + 19*w + 7], [997, 997, -6*w^3 + 12*w^2 + 33*w - 4], [997, 997, 4*w^3 - 11*w^2 - 15*w + 11]]; primes := [ideal : I in primesArray]; heckePol := x^6 - 17*x^4 + 68*x^2 - 16; K := NumberField(heckePol); heckeEigenvaluesArray := [e, 0, 1/2*e^3 - 9/2*e, -1/8*e^5 + 13/8*e^3 - 5*e, -1/8*e^5 + 17/8*e^3 - 19/2*e, -1/4*e^5 + 15/4*e^3 - 25/2*e, -1/8*e^5 + 17/8*e^3 - 13/2*e, -1/4*e^4 + 9/4*e^2 + 1, -1/4*e^4 + 17/4*e^2 - 9, -1/4*e^5 + 19/4*e^3 - 41/2*e, -1/8*e^5 + 9/8*e^3 + 1/2*e, -1/4*e^4 + 9/4*e^2 + 4, 1/8*e^5 - 9/8*e^3 - 1/2*e, 1/4*e^4 - 9/4*e^2 + 2, 3/8*e^5 - 43/8*e^3 + 35/2*e, 1/4*e^4 - 13/4*e^2 + 4, 1/2*e^5 - 17/2*e^3 + 32*e, -1/2*e^5 + 13/2*e^3 - 14*e, 1/4*e^5 - 13/4*e^3 + 10*e, 3/4*e^4 - 39/4*e^2 + 15, -3/4*e^4 + 27/4*e^2 + 3, -e^2 + 8, e^3 - 5*e, e^4 - 12*e^2 + 14, -1/4*e^5 + 17/4*e^3 - 19*e, 1/2*e^5 - 17/2*e^3 + 38*e, 3*e, -1/2*e^4 + 7/2*e^2 + 14, -1/2*e^4 + 13/2*e^2 - 4, 1/4*e^5 - 19/4*e^3 + 35/2*e, e^5 - 29/2*e^3 + 83/2*e, -5/4*e^4 + 53/4*e^2 - 16, 1/4*e^4 - 13/4*e^2 + 2, -1/2*e^5 + 13/2*e^3 - 14*e, 5/8*e^5 - 69/8*e^3 + 49/2*e, -3/4*e^4 + 39/4*e^2 - 12, e^4 - 12*e^2 + 20, 3*e^2 - 12, 3*e^2 - 24, 1/2*e^5 - 15/2*e^3 + 22*e, -1/2*e^5 + 15/2*e^3 - 28*e, 12, -1/4*e^5 + 13/4*e^3 - 10*e, e^4 - 13*e^2 + 28, -3/4*e^5 + 43/4*e^3 - 35*e, 1/2*e^4 - 11/2*e^2 + 18, 1/4*e^5 - 17/4*e^3 + 9*e, e^4 - 13*e^2 + 22, -3/4*e^4 + 39/4*e^2 - 30, 3/4*e^4 - 27/4*e^2 + 6, 6, -1/4*e^5 + 21/4*e^3 - 26*e, e^5 - 31/2*e^3 + 95/2*e, -5/4*e^5 + 67/4*e^3 - 85/2*e, 1/4*e^5 - 19/4*e^3 + 29/2*e, 1/4*e^5 - 19/4*e^3 + 59/2*e, 2*e^2 - 10, 1/4*e^5 - 17/4*e^3 + 15*e, 3/4*e^5 - 47/4*e^3 + 34*e, 2*e^2 + 2, 24, -1/4*e^5 + 9/4*e^3 - 2*e, 5/4*e^5 - 83/4*e^3 + 145/2*e, -5/4*e^4 + 53/4*e^2 - 11, 3/4*e^4 - 43/4*e^2 + 23, -e^5 + 35/2*e^3 - 131/2*e, -6, 3/2*e^4 - 27/2*e^2 + 6, -3/4*e^4 + 27/4*e^2 + 11, -3/4*e^4 + 39/4*e^2 - 19, e^5 - 17*e^3 + 60*e, 4*e^3 - 38*e, -e^4 + 11*e^2 - 18, e^4 - 7*e^2 - 26, -3/4*e^4 + 27/4*e^2 - 9, -3/4*e^4 + 27/4*e^2 - 15, -1/4*e^5 + 29/4*e^3 - 43*e, -1/4*e^5 + 29/4*e^3 - 43*e, -7/4*e^4 + 71/4*e^2 - 6, 3/8*e^5 - 91/8*e^3 + 137/2*e, e^5 - 13*e^3 + 28*e, -5/4*e^5 + 77/4*e^3 - 59*e, -24, -3*e^2 + 30, 1/2*e^5 - 21/2*e^3 + 52*e, 12, 1/2*e^4 - 9/2*e^2 - 8, 5/4*e^5 - 85/4*e^3 + 71*e, -1/4*e^5 + 5/4*e^3 + 5*e, -3/4*e^5 + 39/4*e^3 - 24*e, -3/2*e^4 + 33/2*e^2 - 24, -3*e^2 + 18, 1/4*e^5 - 37/4*e^3 + 61*e, -5/4*e^5 + 77/4*e^3 - 56*e, 5/8*e^5 - 77/8*e^3 + 47/2*e, -5/4*e^4 + 65/4*e^2 - 40, e^5 - 16*e^3 + 55*e, 1/4*e^5 - 13/4*e^3 - 2*e, -3/4*e^5 + 43/4*e^3 - 23*e, -1/2*e^4 + 13/2*e^2 - 44, -1/4*e^5 + 29/4*e^3 - 43*e, -1/4*e^5 + 5/4*e^3 + 14*e, 5/8*e^5 - 85/8*e^3 + 57/2*e, -7/4*e^4 + 59/4*e^2 + 6, -1/8*e^5 + 17/8*e^3 - 9/2*e, 1/4*e^4 + 11/4*e^2 - 38, 6*e^2 - 18, 3*e^2 - 42, 1/2*e^4 - 3/2*e^2 - 14, 3/4*e^5 - 51/4*e^3 + 51*e, -5/4*e^5 + 73/4*e^3 - 50*e, 1/4*e^5 - 5/4*e^3 - 14*e, 5/8*e^5 - 53/8*e^3 + 5/2*e, -1/8*e^5 + 49/8*e^3 - 91/2*e, 5/8*e^5 - 61/8*e^3 + 29/2*e, -7/8*e^5 + 143/8*e^3 - 151/2*e, 1/2*e^5 - 9*e^3 + 89/2*e, -9/4*e^4 + 93/4*e^2 - 15, 3/2*e^4 - 27/2*e^2 + 18, 3*e^2 - 18, -7/4*e^5 + 115/4*e^3 - 97*e, -1/4*e^5 + 13/4*e^3 - 4*e, 3/2*e^4 - 41/2*e^2 + 26, 1/2*e^4 + 1/2*e^2 - 36, -1/2*e^5 + 13/2*e^3 - 23*e, -5/4*e^5 + 65/4*e^3 - 32*e, 3/4*e^4 - 19/4*e^2 - 34, 1/8*e^5 + 23/8*e^3 - 65/2*e, 1/8*e^5 - 41/8*e^3 + 55/2*e, 1/8*e^5 - 17/8*e^3 + 25/2*e, -2*e^5 + 29*e^3 - 83*e, -1/2*e^5 + 13/2*e^3 - 11*e, 1/4*e^4 - 1/4*e^2 + 7, -1/2*e^3 + 5/2*e, -e^5 + 23/2*e^3 - 29/2*e, -3/4*e^4 + 23/4*e^2 + 23, -2*e^4 + 26*e^2 - 46, 3/2*e^4 - 29/2*e^2 + 2, e^3 - 17*e, -7/4*e^4 + 63/4*e^2 - 11, 5/4*e^5 - 87/4*e^3 + 155/2*e, -1/4*e^5 + 25/4*e^3 - 49*e, 3*e^4 - 34*e^2 + 56, 6*e^2 - 30, -3/2*e^4 + 39/2*e^2 - 54, 1/2*e^5 - 9/2*e^3 - 14*e, -3*e^2 - 12, -1/2*e^4 + 1/2*e^2 + 34, 2*e^5 - 32*e^3 + 110*e, 1/2*e^4 - 15/2*e^2 + 34, -3/4*e^5 + 27/4*e^3 + 9*e, e^3 - 23*e, 2*e^4 - 22*e^2 + 36, -1/4*e^4 + 17/4*e^2 - 3, -1/2*e^3 + 41/2*e, 7/8*e^5 - 87/8*e^3 + 47/2*e, 5/4*e^4 - 57/4*e^2 + 40, -1/8*e^5 + 49/8*e^3 - 73/2*e, -1/8*e^5 + 1/8*e^3 - 7/2*e, -5/4*e^5 + 81/4*e^3 - 73*e, 3/2*e^4 - 27/2*e^2 + 18, -2*e^5 + 32*e^3 - 104*e, 1/4*e^5 - 25/4*e^3 + 31*e, 7/4*e^5 - 115/4*e^3 + 94*e, 1/4*e^5 - 25/4*e^3 + 25*e, 7/4*e^4 - 67/4*e^2 - 4, 1/4*e^4 + 11/4*e^2 - 4, 7/4*e^5 - 121/4*e^3 + 233/2*e, -5/4*e^5 + 71/4*e^3 - 121/2*e]; 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;