/* 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![9, 3, -7, -1, 1]; F := NumberField(g); ZF := Integers(F); NN := ideal; primesArray := [ [5, 5, -1/3*w^3 - 2/3*w^2 + 7/3*w + 4], [5, 5, 1/3*w^3 - 4/3*w^2 - 1/3*w + 3], [9, 3, -w], [9, 3, 1/3*w^3 - 1/3*w^2 - 7/3*w + 1], [16, 2, 2], [19, 19, 2/3*w^3 - 2/3*w^2 - 11/3*w], [19, 19, -1/3*w^3 + 1/3*w^2 + 1/3*w + 1], [31, 31, 2/3*w^3 + 1/3*w^2 - 11/3*w - 2], [31, 31, 2/3*w^3 - 5/3*w^2 - 5/3*w + 5], [41, 41, -1/3*w^3 + 4/3*w^2 + 7/3*w - 6], [41, 41, -1/3*w^3 + 4/3*w^2 + 7/3*w - 3], [61, 61, 1/3*w^3 - 4/3*w^2 + 2/3*w + 4], [61, 61, 2/3*w^3 + 1/3*w^2 - 14/3*w - 2], [71, 71, -1/3*w^3 + 4/3*w^2 + 1/3*w - 7], [71, 71, 1/3*w^3 + 2/3*w^2 - 7/3*w], [89, 89, -1/3*w^3 + 1/3*w^2 + 10/3*w - 3], [89, 89, 1/3*w^3 - 1/3*w^2 - 10/3*w - 1], [101, 101, 1/3*w^3 - 1/3*w^2 - 7/3*w - 3], [101, 101, -2/3*w^3 + 5/3*w^2 + 11/3*w - 4], [101, 101, 2/3*w^3 - 5/3*w^2 - 8/3*w + 3], [101, 101, w - 4], [109, 109, 2/3*w^3 + 1/3*w^2 - 8/3*w - 4], [109, 109, -w^3 + 2*w^2 + 4*w - 4], [121, 11, w^3 - w^2 - 4*w + 1], [121, 11, -w^3 + w^2 + 4*w - 2], [131, 131, 4/3*w^3 - 1/3*w^2 - 22/3*w - 1], [131, 131, -w^3 + 7*w + 2], [139, 139, 2/3*w^3 - 2/3*w^2 - 14/3*w + 1], [139, 139, 2*w - 1], [139, 139, 1/3*w^3 + 5/3*w^2 - 7/3*w - 10], [139, 139, -2/3*w^3 + 8/3*w^2 + 5/3*w - 5], [149, 149, w^3 + w^2 - 7*w - 11], [149, 149, -w^3 - w^2 + 5*w + 4], [151, 151, -2/3*w^3 - 4/3*w^2 + 14/3*w + 5], [151, 151, 2/3*w^3 - 8/3*w^2 - 2/3*w + 9], [169, 13, -2/3*w^3 - 1/3*w^2 + 11/3*w], [169, 13, -2/3*w^3 + 5/3*w^2 + 5/3*w - 7], [179, 179, 4/3*w^3 - 7/3*w^2 - 13/3*w + 6], [179, 179, -4/3*w^3 + 1/3*w^2 + 19/3*w + 1], [181, 181, 5/3*w^3 - 8/3*w^2 - 20/3*w + 5], [181, 181, -1/3*w^3 + 1/3*w^2 + 10/3*w - 1], [181, 181, -4/3*w^3 + 1/3*w^2 + 16/3*w + 3], [191, 191, w^2 - 3*w - 1], [191, 191, -1/3*w^3 + 4/3*w^2 + 10/3*w - 3], [199, 199, -w^3 + 3*w^2 + w - 7], [199, 199, -4/3*w^3 + 1/3*w^2 + 19/3*w - 1], [211, 211, -1/3*w^3 - 5/3*w^2 + 4/3*w + 8], [211, 211, w^3 - 3*w^2 - 4*w + 8], [229, 229, -4/3*w^3 + 4/3*w^2 + 13/3*w - 4], [229, 229, -5/3*w^3 + 5/3*w^2 + 23/3*w - 5], [229, 229, 1/3*w^3 - 7/3*w^2 + 2/3*w + 10], [229, 229, -2/3*w^3 + 2/3*w^2 + 2/3*w - 3], [239, 239, 4/3*w^3 - 1/3*w^2 - 19/3*w - 2], [239, 239, -2/3*w^3 + 2/3*w^2 + 11/3*w - 6], [251, 251, 2*w^2 - w - 8], [251, 251, -1/3*w^3 - 2/3*w^2 + 7/3*w - 2], [251, 251, 1/3*w^3 - 4/3*w^2 - 1/3*w + 9], [251, 251, -1/3*w^3 + 7/3*w^2 + 1/3*w - 7], [269, 269, -5/3*w^3 + 8/3*w^2 + 17/3*w - 8], [269, 269, -5/3*w^3 + 11/3*w^2 + 17/3*w - 12], [271, 271, 1/3*w^3 + 2/3*w^2 - 13/3*w - 3], [271, 271, 1/3*w^3 + 2/3*w^2 - 13/3*w - 2], [311, 311, -1/3*w^3 + 7/3*w^2 - 5/3*w - 8], [311, 311, -w^3 + 5*w - 1], [331, 331, -2/3*w^3 - 1/3*w^2 + 8/3*w + 6], [331, 331, -w^3 + 2*w^2 + 4*w - 2], [349, 349, -w^3 + 2*w^2 + w + 1], [349, 349, 1/3*w^3 - 1/3*w^2 - 7/3*w - 4], [349, 349, -4/3*w^3 + 13/3*w^2 + 10/3*w - 11], [349, 349, w - 5], [361, 19, -4/3*w^3 + 4/3*w^2 + 16/3*w - 3], [379, 379, 7/3*w^3 - 1/3*w^2 - 43/3*w - 9], [379, 379, 2*w^3 - 3*w^2 - 9*w + 8], [401, 401, 1/3*w^3 + 2/3*w^2 - 7/3*w - 8], [401, 401, -1/3*w^3 + 10/3*w^2 - 2/3*w - 15], [401, 401, -4/3*w^3 + 4/3*w^2 + 13/3*w - 3], [401, 401, -1/3*w^3 + 4/3*w^2 - 5/3*w + 3], [409, 409, -5/3*w^3 + 8/3*w^2 + 20/3*w - 7], [409, 409, 4/3*w^3 - 1/3*w^2 - 16/3*w - 1], [419, 419, 4/3*w^3 - 16/3*w^2 - 1/3*w + 10], [419, 419, 5/3*w^3 + 7/3*w^2 - 35/3*w - 17], [421, 421, -2*w^3 + 4*w^2 + 7*w - 10], [421, 421, -5/3*w^3 + 8/3*w^2 + 29/3*w - 7], [421, 421, 1/3*w^3 + 2/3*w^2 + 5/3*w - 4], [421, 421, -5/3*w^3 - 1/3*w^2 + 23/3*w + 5], [431, 431, -2/3*w^3 + 5/3*w^2 + 11/3*w - 1], [431, 431, -w^2 - w + 8], [439, 439, -2/3*w^3 + 11/3*w^2 - 1/3*w - 8], [439, 439, -2/3*w^3 + 11/3*w^2 + 8/3*w - 15], [479, 479, w^3 + 2*w^2 - 6*w - 10], [479, 479, -5/3*w^3 + 5/3*w^2 + 14/3*w], [479, 479, -5/3*w^3 + 5/3*w^2 + 23/3*w - 3], [479, 479, -4/3*w^3 + 4/3*w^2 + 13/3*w - 2], [521, 521, -w^3 + 2*w^2 + 5*w + 1], [521, 521, 1/3*w^3 + 2/3*w^2 - 1/3*w - 10], [541, 541, 1/3*w^3 + 5/3*w^2 + 2/3*w - 7], [541, 541, 5/3*w^3 - 5/3*w^2 - 26/3*w], [569, 569, -w - 5], [569, 569, 1/3*w^3 - 1/3*w^2 - 7/3*w + 6], [571, 571, w^3 - 4*w - 8], [571, 571, -1/3*w^3 + 7/3*w^2 + 7/3*w - 4], [599, 599, 5/3*w^3 - 5/3*w^2 - 14/3*w + 4], [599, 599, -4/3*w^3 + 13/3*w^2 + 13/3*w - 15], [599, 599, 2*w^3 - 3*w^2 - 8*w + 5], [599, 599, 7/3*w^3 - 7/3*w^2 - 34/3*w + 6], [601, 601, -4/3*w^3 + 13/3*w^2 + 13/3*w - 13], [601, 601, -w^3 + 8*w + 5], [619, 619, -5/3*w^3 + 11/3*w^2 + 17/3*w - 13], [619, 619, 4/3*w^3 + 2/3*w^2 - 19/3*w - 2], [631, 631, w^3 - w^2 - 7*w + 1], [631, 631, 3*w - 2], [641, 641, -2/3*w^3 + 5/3*w^2 + 2/3*w - 7], [641, 641, -1/3*w^3 + 7/3*w^2 - 5/3*w - 9], [661, 661, -5/3*w^3 + 11/3*w^2 + 20/3*w - 9], [661, 661, w^3 + w^2 - 4*w - 7], [691, 691, -5/3*w^3 + 8/3*w^2 + 17/3*w - 6], [691, 691, 2*w^2 - 3*w - 10], [691, 691, 5/3*w^3 - 2/3*w^2 - 23/3*w - 1], [691, 691, 1/3*w^3 + 5/3*w^2 - 13/3*w - 3], [701, 701, 2/3*w^3 + 4/3*w^2 - 20/3*w - 11], [701, 701, -2/3*w^3 - 1/3*w^2 + 17/3*w + 9], [709, 709, -2/3*w^3 - 7/3*w^2 + 17/3*w + 11], [709, 709, -1/3*w^3 + 10/3*w^2 - 2/3*w - 8], [709, 709, -2/3*w^3 + 11/3*w^2 - 1/3*w - 10], [709, 709, 3*w^2 - 2*w - 14], [719, 719, 7/3*w^3 + 8/3*w^2 - 46/3*w - 21], [719, 719, -2*w^3 + 7*w^2 + 2*w - 13], [719, 719, 2/3*w^3 + 7/3*w^2 - 14/3*w - 9], [719, 719, -w^3 + 4*w^2 + 2*w - 13], [761, 761, 1/3*w^3 + 5/3*w^2 - 1/3*w - 8], [761, 761, 5/3*w^3 - 2/3*w^2 - 14/3*w + 1], [761, 761, -8/3*w^3 + 11/3*w^2 + 38/3*w - 11], [761, 761, -4/3*w^3 + 10/3*w^2 + 19/3*w - 9], [809, 809, -2/3*w^3 + 11/3*w^2 + 5/3*w - 15], [809, 809, 3*w^2 - w - 8], [811, 811, 2/3*w^3 + 7/3*w^2 - 14/3*w - 11], [811, 811, 1/3*w^3 + 8/3*w^2 - 13/3*w - 10], [811, 811, 1/3*w^3 - 10/3*w^2 + 5/3*w + 11], [811, 811, -w^3 + 4*w^2 + 2*w - 11], [821, 821, 2*w^3 - w^2 - 12*w - 5], [821, 821, 1/3*w^3 + 5/3*w^2 - 7/3*w - 14], [829, 829, -2/3*w^3 + 11/3*w^2 + 5/3*w - 10], [829, 829, 3*w^2 - w - 13], [839, 839, 4/3*w^3 - 1/3*w^2 - 25/3*w + 1], [839, 839, -2/3*w^3 + 5/3*w^2 - 1/3*w - 6], [841, 29, 5/3*w^3 - 5/3*w^2 - 20/3*w + 1], [841, 29, -5/3*w^3 + 5/3*w^2 + 20/3*w - 4], [859, 859, -1/3*w^3 - 8/3*w^2 + 13/3*w + 11], [859, 859, -1/3*w^3 + 10/3*w^2 - 5/3*w - 10], [859, 859, 2/3*w^3 - 8/3*w^2 + 1/3*w + 9], [859, 859, -2/3*w^3 + 5/3*w^2 + 2/3*w - 8], [881, 881, -4/3*w^3 + 16/3*w^2 + 4/3*w - 11], [881, 881, 1/3*w^3 - 13/3*w^2 - 4/3*w + 18], [911, 911, -1/3*w^3 + 10/3*w^2 + 1/3*w - 14], [911, 911, -1/3*w^3 + 10/3*w^2 + 1/3*w - 9], [929, 929, 4/3*w^3 - 7/3*w^2 - 22/3*w + 4], [929, 929, 1/3*w^3 + 2/3*w^2 + 2/3*w - 6], [961, 31, 5/3*w^3 - 5/3*w^2 - 20/3*w + 2], [971, 971, -2/3*w^3 + 11/3*w^2 + 2/3*w - 13], [971, 971, 1/3*w^3 + 8/3*w^2 - 10/3*w - 9], [991, 991, -4/3*w^3 + 10/3*w^2 + 16/3*w - 17], [991, 991, -2*w^3 + 4*w^2 + 11*w - 11]]; primes := [ideal : I in primesArray]; heckePol := x^4 - 4*x^3 - 5*x^2 + 25*x - 18; K := NumberField(heckePol); heckeEigenvaluesArray := [e, 3*e^3 - 8*e^2 - 26*e + 42, 2*e^3 - 5*e^2 - 18*e + 26, 2*e^3 - 5*e^2 - 18*e + 26, -e - 1, e^3 - 2*e^2 - 9*e + 10, -2*e^3 + 5*e^2 + 19*e - 26, -1, -3*e^3 + 7*e^2 + 26*e - 32, -7*e^3 + 19*e^2 + 61*e - 96, 6*e^3 - 15*e^2 - 52*e + 78, -6*e^3 + 16*e^2 + 49*e - 80, e^3 - 2*e^2 - 10*e + 10, -e^3 + e^2 + 10*e, -e^3 + 3*e^2 + 8*e - 12, 12*e^3 - 33*e^2 - 103*e + 168, 2*e^3 - 6*e^2 - 18*e + 30, 2*e^3 - 4*e^2 - 18*e + 18, 13*e^3 - 35*e^2 - 110*e + 174, -4*e^3 + 10*e^2 + 37*e - 48, -12*e^3 + 33*e^2 + 102*e - 162, -6*e^3 + 15*e^2 + 53*e - 76, e^3 - 2*e^2 - 7*e + 8, -3*e^3 + 7*e^2 + 25*e - 32, -9*e^3 + 23*e^2 + 80*e - 122, -4*e^3 + 11*e^2 + 37*e - 54, -12*e^3 + 33*e^2 + 99*e - 162, -e^3 + 3*e^2 + 4*e - 16, 10*e^3 - 28*e^2 - 84*e + 140, -5*e^3 + 11*e^2 + 43*e - 50, 5*e^3 - 11*e^2 - 47*e + 58, 9*e^3 - 23*e^2 - 75*e + 108, 3*e^3 - 8*e^2 - 28*e + 54, 13*e^3 - 33*e^2 - 112*e + 172, -13*e^3 + 35*e^2 + 111*e - 182, -e^3 + 2*e^2 + 9*e - 4, 11*e^3 - 30*e^2 - 91*e + 140, 10*e^3 - 29*e^2 - 86*e + 156, -17*e^3 + 47*e^2 + 139*e - 234, -11*e^3 + 29*e^2 + 90*e - 154, 7*e^3 - 20*e^2 - 59*e + 112, -5*e^3 + 12*e^2 + 43*e - 52, 9*e^3 - 25*e^2 - 75*e + 126, 2*e^3 - 5*e^2 - 21*e + 18, -13*e^3 + 32*e^2 + 114*e - 172, 13*e^3 - 35*e^2 - 107*e + 182, -e^3 + 4*e^2 + 7*e - 22, -4*e^3 + 13*e^2 + 33*e - 70, -8*e^3 + 25*e^2 + 66*e - 130, 9*e^3 - 25*e^2 - 73*e + 128, -3*e^3 + 8*e^2 + 22*e - 38, -2*e^3 + 5*e^2 + 21*e - 20, -3*e^3 + 5*e^2 + 26*e - 24, 4*e^3 - 11*e^2 - 32*e + 60, -9*e^3 + 22*e^2 + 84*e - 108, 2*e^3 - 7*e^2 - 11*e + 42, 5*e^3 - 13*e^2 - 46*e + 60, -10*e^3 + 25*e^2 + 85*e - 126, 5*e^3 - 12*e^2 - 42*e + 66, -13*e^3 + 34*e^2 + 108*e - 162, 13*e^3 - 34*e^2 - 108*e + 160, 2*e^3 - 5*e^2 - 15*e + 22, -9*e^3 + 24*e^2 + 75*e - 114, -3*e^3 + 10*e^2 + 19*e - 42, -12*e^3 + 29*e^2 + 107*e - 154, -29*e^3 + 78*e^2 + 250*e - 400, 6*e^3 - 18*e^2 - 51*e + 88, -8*e^3 + 20*e^2 + 75*e - 100, -21*e^3 + 58*e^2 + 177*e - 296, 15*e^3 - 42*e^2 - 122*e + 218, 7*e^3 - 15*e^2 - 63*e + 80, 7*e^3 - 20*e^2 - 53*e + 106, -8*e^3 + 19*e^2 + 66*e - 92, -3*e^3 + 8*e^2 + 16*e - 30, -16*e^3 + 43*e^2 + 137*e - 240, -20*e^3 + 54*e^2 + 176*e - 270, -6*e^3 + 14*e^2 + 52*e - 54, e^3 - 5*e^2 - 11*e + 40, -15*e^3 + 41*e^2 + 133*e - 224, -6*e^3 + 15*e^2 + 48*e - 72, 8*e^3 - 21*e^2 - 73*e + 102, 9*e^3 - 24*e^2 - 68*e + 118, 22*e^3 - 58*e^2 - 183*e + 296, -4*e^3 + 9*e^2 + 38*e - 58, 9*e^3 - 23*e^2 - 80*e + 130, -5*e^3 + 14*e^2 + 47*e - 66, -21*e^3 + 56*e^2 + 170*e - 276, -21*e^3 + 54*e^2 + 180*e - 280, -6*e^3 + 18*e^2 + 44*e - 88, 11*e^3 - 30*e^2 - 87*e + 138, -9*e^3 + 23*e^2 + 78*e - 144, 6*e^3 - 16*e^2 - 48*e + 96, -6*e^3 + 11*e^2 + 56*e - 60, -3*e^3 + 10*e^2 + 22*e - 42, 3*e^3 - 5*e^2 - 30*e + 42, 9*e^3 - 25*e^2 - 70*e + 142, -25*e^3 + 67*e^2 + 218*e - 362, 2*e^2 - 7*e - 12, -16*e^3 + 43*e^2 + 131*e - 228, -19*e^3 + 48*e^2 + 160*e - 236, -19*e^3 + 51*e^2 + 171*e - 266, 19*e^3 - 51*e^2 - 166*e + 264, -30*e^3 + 79*e^2 + 252*e - 396, -5*e^3 + 17*e^2 + 38*e - 96, -28*e^3 + 73*e^2 + 246*e - 384, -23*e^3 + 65*e^2 + 200*e - 346, -6*e^3 + 15*e^2 + 47*e - 76, 24*e^3 - 63*e^2 - 203*e + 314, 2*e^3 - 2*e^2 - 23*e + 14, 3*e^3 - 11*e^2 - 19*e + 62, 3*e^2 + 2*e - 16, 28*e^3 - 75*e^2 - 239*e + 384, 26*e^3 - 72*e^2 - 217*e + 360, -4*e^3 + 9*e^2 + 37*e - 44, -7*e^3 + 19*e^2 + 59*e - 104, 22*e^3 - 61*e^2 - 198*e + 332, 21*e^3 - 53*e^2 - 171*e + 242, 3*e^3 - 8*e^2 - 31*e + 62, -11*e^3 + 31*e^2 + 93*e - 142, -6*e^3 + 14*e^2 + 43*e - 60, 4*e^3 - 7*e^2 - 51*e + 36, e^3 + 2*e^2 - 10*e - 14, -11*e^3 + 29*e^2 + 102*e - 170, 21*e^3 - 61*e^2 - 174*e + 310, 3*e^3 - 6*e^2 - 36*e + 46, 5*e^3 - 17*e^2 - 25*e + 90, -e^3 + 3*e^2 - e - 30, 6*e^3 - 20*e^2 - 41*e + 102, 4*e^3 - 11*e^2 - 39*e + 54, -23*e^3 + 59*e^2 + 206*e - 318, -e^2 - e - 12, e^3 - 6*e^2 - 8*e + 42, -6*e^3 + 16*e^2 + 52*e - 78, -19*e^3 + 52*e^2 + 171*e - 288, -10*e^3 + 32*e^2 + 75*e - 168, -6*e^3 + 19*e^2 + 50*e - 92, -3*e^3 + 11*e^2 + 27*e - 74, -8*e^3 + 21*e^2 + 55*e - 98, -17*e^3 + 45*e^2 + 143*e - 218, -28*e^3 + 76*e^2 + 235*e - 396, e^3 + 2*e^2 - 6*e - 30, 31*e^3 - 79*e^2 - 262*e + 406, 16*e^3 - 45*e^2 - 127*e + 220, 5*e^2 - 4*e - 60, -14*e^3 + 36*e^2 + 114*e - 180, -23*e^3 + 66*e^2 + 193*e - 332, 22*e^3 - 61*e^2 - 186*e + 298, -30*e^3 + 83*e^2 + 252*e - 424, -19*e^3 + 50*e^2 + 152*e - 244, 30*e^3 - 81*e^2 - 249*e + 406, 7*e^3 - 23*e^2 - 48*e + 112, e^3 - 2*e^2 - 8*e - 30, -17*e^3 + 45*e^2 + 147*e - 252, 9*e^3 - 24*e^2 - 83*e + 114, -14*e^3 + 42*e^2 + 113*e - 222, -3*e^3 + 10*e^2 + 33*e - 84, -13*e^3 + 35*e^2 + 103*e - 204, 12*e^3 - 33*e^2 - 98*e + 146, 9*e^3 - 19*e^2 - 83*e + 114, 6*e^3 - 14*e^2 - 51*e + 54, -34*e^3 + 92*e^2 + 298*e - 460, 29*e^3 - 81*e^2 - 240*e + 380]; 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;