/* 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![44, 0, -14, 0, 1]; F := NumberField(g); ZF := Integers(F); NN := ideal; primesArray := [ [4, 2, -1/2*w^3 + w^2 + 4*w - 8], [11, 11, 1/2*w^3 - 3/2*w^2 - 4*w + 11], [11, 11, -1/2*w^2 - w + 2], [11, 11, -1/2*w^2 + w + 2], [19, 19, 1/2*w^3 - 1/2*w^2 - 4*w + 5], [19, 19, 1/2*w^3 + w^2 - 4*w - 9], [19, 19, 1/2*w^3 - w^2 - 4*w + 9], [19, 19, 1/2*w^3 + 1/2*w^2 - 4*w - 5], [25, 5, 1/2*w^2 - 1], [29, 29, 1/2*w^3 - 4*w - 1], [29, 29, -1/2*w^3 + 4*w - 1], [31, 31, -w - 1], [31, 31, w - 1], [41, 41, 1/2*w^3 + 1/2*w^2 - 4*w - 2], [41, 41, -1/2*w^3 + 1/2*w^2 + 4*w - 2], [49, 7, -1/2*w^3 + 1/2*w^2 + 5*w - 7], [49, 7, 3/2*w^3 - 7/2*w^2 - 13*w + 29], [59, 59, -1/2*w^3 - 3/2*w^2 + 3*w + 10], [59, 59, 1/2*w^3 - 3/2*w^2 - 3*w + 10], [61, 61, 1/2*w^2 + w - 6], [61, 61, 1/2*w^2 - w - 6], [71, 71, w^3 - 5/2*w^2 - 8*w + 20], [71, 71, -w^3 + 5/2*w^2 + 10*w - 24], [81, 3, -3], [101, 101, -1/2*w^3 + 1/2*w^2 + 4*w - 1], [101, 101, 1/2*w^3 + 1/2*w^2 - 4*w - 1], [109, 109, 3/2*w^2 + w - 12], [109, 109, 3/2*w^2 - w - 12], [149, 149, 1/2*w^3 + 2*w^2 - 4*w - 15], [149, 149, -1/2*w^3 + 2*w^2 + 4*w - 15], [151, 151, 1/2*w^3 - 1/2*w^2 - 4*w + 8], [151, 151, -w^3 + 5/2*w^2 + 8*w - 18], [151, 151, -w^3 + 3/2*w^2 + 10*w - 18], [151, 151, -1/2*w^3 - 1/2*w^2 + 4*w + 8], [179, 179, 1/2*w^3 + w^2 - 4*w - 5], [179, 179, -1/2*w^3 + w^2 + 4*w - 5], [181, 181, 1/2*w^3 - 5*w - 3], [181, 181, w^3 - 1/2*w^2 - 7*w - 1], [181, 181, -1/2*w^3 - 5/2*w^2 + 4*w + 15], [181, 181, 1/2*w^3 - 5*w + 3], [191, 191, w^3 - 2*w^2 - 7*w + 13], [191, 191, -w^3 - 2*w^2 + 7*w + 13], [199, 199, -5/2*w^2 - 2*w + 18], [199, 199, -5/2*w^2 + 2*w + 18], [241, 241, -3/2*w^3 + 7/2*w^2 + 14*w - 30], [241, 241, -3/2*w^3 + 5/2*w^2 + 16*w - 30], [251, 251, 3/2*w^2 - w - 13], [251, 251, 3/2*w^2 + w - 13], [269, 269, 1/2*w^3 + 1/2*w^2 - 3*w - 10], [269, 269, -w^3 + 1/2*w^2 + 7*w - 8], [269, 269, w^3 + 1/2*w^2 - 7*w - 8], [269, 269, -1/2*w^3 + 1/2*w^2 + 3*w - 10], [271, 271, -w^3 + 8*w + 5], [271, 271, -2*w^2 + 2*w + 15], [271, 271, 2*w^2 + 2*w - 15], [271, 271, w^3 - 8*w + 5], [281, 281, -2*w + 3], [281, 281, w^3 - 2*w^2 - 12*w + 25], [311, 311, 1/2*w^3 + 5/2*w^2 - 3*w - 17], [311, 311, -1/2*w^3 + 5/2*w^2 + 3*w - 17], [331, 331, -1/2*w^3 + 3/2*w^2 + 5*w - 10], [331, 331, 1/2*w^3 + 3/2*w^2 - 5*w - 10], [349, 349, -1/2*w^2 + 3*w - 3], [349, 349, -w^3 + 5/2*w^2 + 11*w - 25], [379, 379, 5/2*w^2 - w - 21], [379, 379, 5/2*w^2 + w - 21], [389, 389, 3/2*w^2 - w - 14], [389, 389, 1/2*w^3 - 5/2*w^2 - 3*w + 16], [389, 389, -1/2*w^3 - 5/2*w^2 + 3*w + 16], [389, 389, 3/2*w^2 + w - 14], [409, 409, w^3 + w^2 - 8*w - 7], [409, 409, -w^3 + w^2 + 8*w - 7], [419, 419, 3/2*w^3 - 5/2*w^2 - 15*w + 28], [419, 419, 3/2*w^3 - 7/2*w^2 - 13*w + 28], [439, 439, 1/2*w^2 + 2*w - 9], [439, 439, -3/2*w^2 + 2*w + 6], [439, 439, -3/2*w^2 - 2*w + 6], [439, 439, 1/2*w^2 - 2*w - 9], [449, 449, -w^3 + 1/2*w^2 + 6*w - 1], [449, 449, 1/2*w^2 + 2*w - 5], [449, 449, 1/2*w^2 - 2*w - 5], [449, 449, w^3 + 1/2*w^2 - 6*w - 1], [461, 461, w^3 + 3/2*w^2 - 7*w - 9], [461, 461, -w^3 + 3/2*w^2 + 7*w - 9], [491, 491, -1/2*w^3 - 1/2*w^2 + 6*w + 7], [491, 491, -5/2*w^2 + w + 16], [491, 491, 5/2*w^2 + w - 16], [491, 491, 1/2*w^3 - 1/2*w^2 - 6*w + 7], [499, 499, -1/2*w^3 + 5/2*w^2 + 4*w - 19], [499, 499, 1/2*w^3 + 5/2*w^2 - 4*w - 19], [541, 541, -1/2*w^3 + 3/2*w^2 + 4*w - 7], [541, 541, 1/2*w^3 + 3/2*w^2 - 4*w - 7], [569, 569, 1/2*w^2 + 2*w - 2], [569, 569, 1/2*w^2 - 2*w - 2], [571, 571, -2*w^3 + 9/2*w^2 + 17*w - 39], [571, 571, 1/2*w^3 - 1/2*w^2 - 5*w - 2], [571, 571, -1/2*w^3 - 1/2*w^2 + 5*w - 2], [571, 571, w^3 - 5/2*w^2 - 11*w + 27], [599, 599, -w^3 + 2*w^2 + 8*w - 13], [599, 599, w^3 + 2*w^2 - 8*w - 13], [601, 601, 1/2*w^2 + 2*w - 4], [601, 601, 1/2*w^2 - 2*w - 4], [619, 619, -1/2*w^3 + 2*w^2 + 6*w - 13], [619, 619, 1/2*w^3 + 2*w^2 - 6*w - 13], [631, 631, -w^3 - 1/2*w^2 + 6*w - 2], [631, 631, w^3 - 1/2*w^2 - 6*w - 2], [641, 641, w^3 - 8*w - 1], [641, 641, -1/2*w^3 - 1/2*w^2 + 5*w - 1], [641, 641, 1/2*w^3 - 1/2*w^2 - 5*w - 1], [641, 641, w^3 - 8*w + 1], [661, 661, -1/2*w^3 + 7/2*w^2 + 2*w - 25], [661, 661, 3/2*w^3 - 9/2*w^2 - 11*w + 32], [661, 661, -5/2*w^3 + 13/2*w^2 + 23*w - 56], [661, 661, 1/2*w^3 + 7/2*w^2 - 2*w - 25], [691, 691, 1/2*w^3 + 7/2*w^2 - 3*w - 28], [691, 691, -1/2*w^3 + 7/2*w^2 + 3*w - 28], [701, 701, -1/2*w^3 + 1/2*w^2 + 5*w - 10], [701, 701, 3/2*w^3 - 5/2*w^2 - 17*w + 34], [709, 709, 1/2*w^3 - 5/2*w^2 - 6*w + 17], [709, 709, w^3 + 5/2*w^2 - 7*w - 14], [709, 709, -w^3 + 5/2*w^2 + 7*w - 14], [709, 709, -1/2*w^3 - 5/2*w^2 + 6*w + 17], [719, 719, -w^3 + 7/2*w^2 + 8*w - 23], [719, 719, w^3 + 7/2*w^2 - 8*w - 23], [751, 751, 7/2*w^2 + 2*w - 27], [751, 751, 7/2*w^2 - 2*w - 27], [761, 761, -1/2*w^3 + 3/2*w^2 + 3*w - 13], [761, 761, 1/2*w^3 + 3/2*w^2 - 3*w - 13], [769, 769, -w^3 + 7/2*w^2 + 8*w - 25], [769, 769, w^3 + 7/2*w^2 - 8*w - 25], [809, 809, 2*w^3 - 7/2*w^2 - 20*w + 40], [809, 809, -1/2*w^2 + 2*w - 4], [811, 811, -1/2*w^2 - 3*w + 8], [811, 811, 1/2*w^3 + 3/2*w^2 - 3*w - 18], [811, 811, -1/2*w^3 + 3/2*w^2 + 3*w - 18], [811, 811, 1/2*w^2 - 3*w - 8], [821, 821, 3/2*w^3 - 7/2*w^2 - 16*w + 37], [821, 821, -3/2*w^3 + 7/2*w^2 + 12*w - 29], [839, 839, 3*w^2 - 2*w - 23], [839, 839, 3*w^2 + 2*w - 23], [841, 29, -5/2*w^2 + 16], [859, 859, 5/2*w^2 + 3*w - 16], [859, 859, 5/2*w^2 - 3*w - 16], [911, 911, 3*w^2 - 2*w - 17], [911, 911, 3*w^2 + 2*w - 17], [919, 919, 3*w^2 - w - 23], [919, 919, -2*w^2 + 3*w + 15], [919, 919, -2*w^2 - 3*w + 15], [919, 919, 3*w^2 + w - 23], [941, 941, 3/2*w^2 - 3*w - 2], [941, 941, 2*w^3 - 11/2*w^2 - 17*w + 42], [961, 31, -w^2 + 13], [971, 971, 1/2*w^3 + 1/2*w^2 - 6*w - 5], [971, 971, -1/2*w^3 + 1/2*w^2 + 6*w - 5], [991, 991, w^3 + 3/2*w^2 - 8*w - 8], [991, 991, -w^3 + 3/2*w^2 + 8*w - 8]]; primes := [ideal : I in primesArray]; heckePol := x^8 - 36*x^6 + 424*x^4 - 1648*x^2 + 320; K := NumberField(heckePol); heckeEigenvaluesArray := [e, -1/8*e^6 + 3*e^4 - 18*e^2 + 8, -1/8*e^5 + 5/2*e^3 - 11*e, -1/8*e^5 + 5/2*e^3 - 11*e, 1/8*e^5 - 3*e^3 + 17*e, 1/8*e^6 - 11/4*e^4 + 14*e^2, 1/8*e^6 - 11/4*e^4 + 14*e^2, 1/8*e^5 - 3*e^3 + 17*e, 1/8*e^6 - 11/4*e^4 + 14*e^2 + 6, 1/16*e^7 - 3/2*e^5 + 10*e^3 - 17*e, 1/16*e^7 - 3/2*e^5 + 10*e^3 - 17*e, -1/2*e^3 + 6*e, -1/2*e^3 + 6*e, -1/16*e^7 + 11/8*e^5 - 13/2*e^3 - 7*e, -1/16*e^7 + 11/8*e^5 - 13/2*e^3 - 7*e, -1/16*e^7 + 13/8*e^5 - 12*e^3 + 21*e, -1/16*e^7 + 13/8*e^5 - 12*e^3 + 21*e, -1/8*e^6 + 5/2*e^4 - 11*e^2, -1/8*e^6 + 5/2*e^4 - 11*e^2, 1/4*e^4 - 2*e^2 - 12, 1/4*e^4 - 2*e^2 - 12, -1/4*e^6 + 11/2*e^4 - 29*e^2 + 8, -1/4*e^6 + 11/2*e^4 - 29*e^2 + 8, -1/4*e^6 + 11/2*e^4 - 29*e^2 + 18, 1/16*e^7 - 5/4*e^5 + 7/2*e^3 + 23*e, 1/16*e^7 - 5/4*e^5 + 7/2*e^3 + 23*e, -1/4*e^4 + 5*e^2 - 20, -1/4*e^4 + 5*e^2 - 20, 1/4*e^6 - 23/4*e^4 + 33*e^2 - 20, 1/4*e^6 - 23/4*e^4 + 33*e^2 - 20, 1/4*e^6 - 11/2*e^4 + 27*e^2 + 8, 1/8*e^7 - 11/4*e^5 + 27/2*e^3 + 10*e, 1/8*e^7 - 11/4*e^5 + 27/2*e^3 + 10*e, 1/4*e^6 - 11/2*e^4 + 27*e^2 + 8, 3/8*e^5 - 7*e^3 + 25*e, 3/8*e^5 - 7*e^3 + 25*e, 1/16*e^7 - 7/4*e^5 + 13*e^3 - 15*e, -1/16*e^7 + 7/4*e^5 - 29/2*e^3 + 35*e, -1/16*e^7 + 7/4*e^5 - 29/2*e^3 + 35*e, 1/16*e^7 - 7/4*e^5 + 13*e^3 - 15*e, 1/4*e^5 - 9/2*e^3 + 14*e, 1/4*e^5 - 9/2*e^3 + 14*e, 1/4*e^6 - 6*e^4 + 34*e^2, 1/4*e^6 - 6*e^4 + 34*e^2, -1/16*e^7 + 15/8*e^5 - 33/2*e^3 + 35*e, -1/16*e^7 + 15/8*e^5 - 33/2*e^3 + 35*e, 1/8*e^6 - 13/4*e^4 + 24*e^2 - 28, 1/8*e^6 - 13/4*e^4 + 24*e^2 - 28, -1/2*e^6 + 47/4*e^4 - 68*e^2 + 20, -3/4*e^4 + 11*e^2 - 20, -3/4*e^4 + 11*e^2 - 20, -1/2*e^6 + 47/4*e^4 - 68*e^2 + 20, -1/4*e^5 + 5*e^3 - 24*e, -1/4*e^6 + 13/2*e^4 - 41*e^2 + 12, -1/4*e^6 + 13/2*e^4 - 41*e^2 + 12, -1/4*e^5 + 5*e^3 - 24*e, -1/16*e^7 + 9/8*e^5 - e^3 - 37*e, -1/16*e^7 + 9/8*e^5 - e^3 - 37*e, 1/2*e^6 - 23/2*e^4 + 66*e^2 - 28, 1/2*e^6 - 23/2*e^4 + 66*e^2 - 28, 1/8*e^7 - 27/8*e^5 + 28*e^3 - 71*e, 1/8*e^7 - 27/8*e^5 + 28*e^3 - 71*e, -3/16*e^7 + 19/4*e^5 - 69/2*e^3 + 63*e, -3/16*e^7 + 19/4*e^5 - 69/2*e^3 + 63*e, -5/8*e^6 + 14*e^4 - 78*e^2 + 40, -5/8*e^6 + 14*e^4 - 78*e^2 + 40, -3/4*e^6 + 67/4*e^4 - 90*e^2 + 20, 1/4*e^6 - 19/4*e^4 + 16*e^2 + 20, 1/4*e^6 - 19/4*e^4 + 16*e^2 + 20, -3/4*e^6 + 67/4*e^4 - 90*e^2 + 20, 1/16*e^7 - 11/8*e^5 + 15/2*e^3 - 5*e, 1/16*e^7 - 11/8*e^5 + 15/2*e^3 - 5*e, 1/8*e^5 - 3/2*e^3 - 5*e, 1/8*e^5 - 3/2*e^3 - 5*e, -1/4*e^6 + 6*e^4 - 35*e^2 + 20, 1/8*e^7 - 13/4*e^5 + 55/2*e^3 - 86*e, 1/8*e^7 - 13/4*e^5 + 55/2*e^3 - 86*e, -1/4*e^6 + 6*e^4 - 35*e^2 + 20, -1/16*e^7 + 11/8*e^5 - 9*e^3 + 21*e, 3/16*e^7 - 35/8*e^5 + 55/2*e^3 - 43*e, 3/16*e^7 - 35/8*e^5 + 55/2*e^3 - 43*e, -1/16*e^7 + 11/8*e^5 - 9*e^3 + 21*e, 1/16*e^7 - 3/2*e^5 + 11*e^3 - 33*e, 1/16*e^7 - 3/2*e^5 + 11*e^3 - 33*e, -1/4*e^7 + 43/8*e^5 - 49/2*e^3 - 29*e, -1/8*e^6 + 13/4*e^4 - 26*e^2 + 48, -1/8*e^6 + 13/4*e^4 - 26*e^2 + 48, -1/4*e^7 + 43/8*e^5 - 49/2*e^3 - 29*e, 5/8*e^6 - 59/4*e^4 + 86*e^2 - 20, 5/8*e^6 - 59/4*e^4 + 86*e^2 - 20, 3/16*e^7 - 5*e^5 + 77/2*e^3 - 67*e, 3/16*e^7 - 5*e^5 + 77/2*e^3 - 67*e, 1/16*e^7 - 13/8*e^5 + 11*e^3 - e, 1/16*e^7 - 13/8*e^5 + 11*e^3 - e, 5/8*e^6 - 15*e^4 + 89*e^2 - 28, 1/8*e^7 - 23/8*e^5 + 27/2*e^3 + 27*e, 1/8*e^7 - 23/8*e^5 + 27/2*e^3 + 27*e, 5/8*e^6 - 15*e^4 + 89*e^2 - 28, -1/8*e^7 + 7/2*e^5 - 57/2*e^3 + 66*e, -1/8*e^7 + 7/2*e^5 - 57/2*e^3 + 66*e, -3/16*e^7 + 29/8*e^5 - 12*e^3 - 33*e, -3/16*e^7 + 29/8*e^5 - 12*e^3 - 33*e, 5/8*e^5 - 23/2*e^3 + 37*e, 5/8*e^5 - 23/2*e^3 + 37*e, 3/4*e^6 - 35/2*e^4 + 99*e^2 - 12, 3/4*e^6 - 35/2*e^4 + 99*e^2 - 12, 1/16*e^7 - 9/8*e^5 + 3*e^3 + 17*e, 1/16*e^7 - 17/8*e^5 + 49/2*e^3 - 89*e, 1/16*e^7 - 17/8*e^5 + 49/2*e^3 - 89*e, 1/16*e^7 - 9/8*e^5 + 3*e^3 + 17*e, -1/4*e^6 + 23/4*e^4 - 31*e^2 + 8, 1/2*e^6 - 43/4*e^4 + 54*e^2 - 8, 1/2*e^6 - 43/4*e^4 + 54*e^2 - 8, -1/4*e^6 + 23/4*e^4 - 31*e^2 + 8, -5/8*e^6 + 55/4*e^4 - 68*e^2 - 32, -5/8*e^6 + 55/4*e^4 - 68*e^2 - 32, -1/4*e^6 + 21/4*e^4 - 24*e^2 - 8, -1/4*e^6 + 21/4*e^4 - 24*e^2 - 8, -1/16*e^7 + 7/4*e^5 - 15*e^3 + 37*e, -3/16*e^7 + 7/2*e^5 - 11/2*e^3 - 99*e, -3/16*e^7 + 7/2*e^5 - 11/2*e^3 - 99*e, -1/16*e^7 + 7/4*e^5 - 15*e^3 + 37*e, -7/2*e^3 + 38*e, -7/2*e^3 + 38*e, -3/4*e^6 + 35/2*e^4 - 102*e^2 + 52, -3/4*e^6 + 35/2*e^4 - 102*e^2 + 52, -3/8*e^6 + 33/4*e^4 - 40*e^2 - 2, -3/8*e^6 + 33/4*e^4 - 40*e^2 - 2, 3/8*e^6 - 33/4*e^4 + 45*e^2 - 10, 3/8*e^6 - 33/4*e^4 + 45*e^2 - 10, 5/8*e^6 - 55/4*e^4 + 73*e^2 - 10, 5/8*e^6 - 55/4*e^4 + 73*e^2 - 10, -3/8*e^5 + 7*e^3 - 33*e, -5/8*e^6 + 53/4*e^4 - 66*e^2 + 28, -5/8*e^6 + 53/4*e^4 - 66*e^2 + 28, -3/8*e^5 + 7*e^3 - 33*e, 5/4*e^4 - 19*e^2 + 32, 5/4*e^4 - 19*e^2 + 32, -1/2*e^4 + 9*e^2 - 40, -1/2*e^4 + 9*e^2 - 40, e^6 - 47/2*e^4 + 133*e^2 - 2, -1/8*e^7 + 19/8*e^5 - 9/2*e^3 - 53*e, -1/8*e^7 + 19/8*e^5 - 9/2*e^3 - 53*e, 1/4*e^5 - 8*e^3 + 52*e, 1/4*e^5 - 8*e^3 + 52*e, -1/2*e^6 + 10*e^4 - 41*e^2 - 40, -1/8*e^7 + 15/4*e^5 - 35*e^3 + 104*e, -1/8*e^7 + 15/4*e^5 - 35*e^3 + 104*e, -1/2*e^6 + 10*e^4 - 41*e^2 - 40, 3/16*e^7 - 4*e^5 + 37/2*e^3 + 17*e, 3/16*e^7 - 4*e^5 + 37/2*e^3 + 17*e, 3/8*e^6 - 35/4*e^4 + 51*e^2 + 22, -1/8*e^7 + 33/8*e^5 - 40*e^3 + 105*e, -1/8*e^7 + 33/8*e^5 - 40*e^3 + 105*e, 1/8*e^7 - 3*e^5 + 18*e^3 - 4*e, 1/8*e^7 - 3*e^5 + 18*e^3 - 4*e]; heckeEigenvalues := AssociativeArray(); for i := 1 to #heckeEigenvaluesArray do heckeEigenvalues[primes[i]] := heckeEigenvaluesArray[i]; end for; ALEigenvalues := AssociativeArray(); // 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;