/* 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, -1, -5, -1, 1]; F := NumberField(g); ZF := Integers(F); NN := ideal; primesArray := [ [5, 5, -w^3 + w^2 + 5*w], [7, 7, -w^3 + 2*w^2 + 3*w - 3], [7, 7, w^3 - 2*w^2 - 3*w], [13, 13, -w^2 + w + 3], [13, 13, -w^2 + w + 2], [16, 2, 2], [23, 23, -w^2 + 3*w + 1], [23, 23, -2*w^3 + 3*w^2 + 9*w - 2], [25, 5, w^3 - 2*w^2 - 2*w + 2], [49, 7, w^3 - w^2 - 6*w - 1], [53, 53, 2*w^3 - 2*w^2 - 8*w - 3], [53, 53, 2*w^3 - 2*w^2 - 8*w - 1], [67, 67, 2*w^3 - 4*w^2 - 7*w + 2], [67, 67, -2*w^3 + 4*w^2 + 6*w - 1], [81, 3, -3], [83, 83, 2*w^3 - 3*w^2 - 6*w - 1], [83, 83, 3*w^3 - 4*w^2 - 12*w + 1], [103, 103, 3*w^3 - 4*w^2 - 12*w - 1], [103, 103, 2*w^3 - 3*w^2 - 6*w + 1], [107, 107, w^3 - w^2 - 3*w - 3], [107, 107, 2*w^3 - 2*w^2 - 9*w], [109, 109, -3*w^3 + 5*w^2 + 10*w - 5], [109, 109, -2*w^3 + 3*w^2 + 9*w + 1], [109, 109, -2*w^3 + 2*w^2 + 7*w], [109, 109, w^2 - 3*w - 4], [121, 11, 3*w^3 - 4*w^2 - 12*w], [121, 11, 2*w^2 - 3*w - 6], [139, 139, w^3 - 7*w - 1], [139, 139, -w^3 + 2*w^2 + 5*w - 4], [139, 139, 3*w^3 - 3*w^2 - 14*w - 2], [139, 139, -3*w^3 + 5*w^2 + 13*w - 2], [149, 149, -w^2 + 4*w + 1], [149, 149, -3*w^3 + 4*w^2 + 14*w - 1], [149, 149, 2*w^2 - 3*w - 5], [149, 149, -w^3 + 3*w^2 + 3*w - 4], [167, 167, -w^3 - w^2 + 7*w + 4], [167, 167, -4*w^3 + 6*w^2 + 15*w - 4], [169, 13, w^3 - w^2 - 6*w + 4], [173, 173, w^2 - 3*w - 5], [173, 173, 2*w^3 - 2*w^2 - 11*w], [179, 179, 2*w^3 - 2*w^2 - 9*w + 1], [179, 179, w^3 - w^2 - 3*w - 4], [179, 179, w^2 - 5], [179, 179, w^3 - 6*w - 1], [197, 197, w^3 + w^2 - 7*w - 6], [197, 197, 2*w^3 - 2*w^2 - 9*w + 2], [223, 223, -w^2 + 7], [223, 223, 2*w^2 - w - 4], [227, 227, 2*w^3 - 2*w^2 - 11*w - 2], [227, 227, w^3 - w^2 - 7*w - 1], [233, 233, w^3 - w^2 - 7*w], [233, 233, -2*w^3 + 2*w^2 + 11*w + 1], [257, 257, -2*w^3 + 4*w^2 + 8*w - 1], [257, 257, 2*w^2 - 4*w - 7], [277, 277, -4*w^3 + 6*w^2 + 15*w - 3], [277, 277, -3*w^3 + 5*w^2 + 9*w], [281, 281, -2*w^3 + 5*w^2 + 3*w - 5], [281, 281, -2*w^3 + 5*w^2 + 5*w - 7], [281, 281, 2*w^3 - 5*w^2 - 5*w + 4], [281, 281, -4*w^3 + 7*w^2 + 15*w - 4], [283, 283, 3*w^3 - 4*w^2 - 13*w - 3], [283, 283, -w^3 + 2*w^2 + w - 4], [313, 313, -2*w^3 + 4*w^2 + 5*w - 5], [313, 313, 3*w^3 - 5*w^2 - 11*w], [347, 347, -w^3 + 2*w^2 + w - 5], [347, 347, 3*w^3 - 4*w^2 - 13*w - 4], [353, 353, 3*w^3 - 5*w^2 - 12*w + 1], [353, 353, -w^3 + 3*w^2 - 5], [361, 19, 3*w^3 - 3*w^2 - 13*w - 9], [361, 19, 2*w^3 - 2*w^2 - 7*w + 4], [373, 373, -3*w^3 + 4*w^2 + 11*w + 1], [373, 373, -3*w^3 + 4*w^2 + 11*w], [383, 383, 3*w^3 - 5*w^2 - 13*w + 1], [383, 383, 2*w^2 - 5*w - 6], [397, 397, 4*w^3 - 5*w^2 - 19*w - 1], [397, 397, 2*w^3 - 2*w^2 - 9*w - 7], [431, 431, 2*w^3 - 2*w^2 - 7*w - 5], [431, 431, 3*w^3 - 6*w^2 - 11*w + 3], [431, 431, 3*w^3 - 3*w^2 - 13*w], [431, 431, w^3 - 4*w^2 + w + 8], [457, 457, 4*w^3 - 7*w^2 - 13*w], [457, 457, -3*w^2 + 4*w + 5], [463, 463, -3*w^3 + 5*w^2 + 11*w + 1], [463, 463, 2*w^3 - 4*w^2 - 5*w + 6], [487, 487, -w^3 + 4*w^2 - 7], [487, 487, -2*w^3 + 5*w^2 + 6*w - 5], [499, 499, -6*w^3 + 8*w^2 + 25*w - 1], [499, 499, -w^3 + 4*w^2 - 5], [499, 499, -2*w^3 + 5*w^2 + 6*w - 7], [499, 499, 3*w^3 - 5*w^2 - 7*w], [509, 509, -4*w^3 + 8*w^2 + 15*w - 8], [509, 509, 3*w^3 - 4*w^2 - 10*w - 2], [509, 509, -3*w^3 + 3*w^2 + 11*w + 6], [509, 509, 4*w^3 - 5*w^2 - 16*w], [521, 521, -4*w^3 + 5*w^2 + 15*w - 2], [521, 521, w^3 - w^2 - 8*w + 1], [521, 521, -4*w^3 + 7*w^2 + 12*w - 6], [521, 521, 3*w^3 - 3*w^2 - 16*w - 1], [523, 523, 3*w^3 - w^2 - 17*w - 8], [523, 523, -5*w^3 + 5*w^2 + 23*w + 4], [529, 23, 3*w^3 - 6*w^2 - 10*w + 2], [547, 547, -2*w^3 + 5*w^2 + 6*w - 6], [547, 547, -w^3 + 4*w^2 - 6], [557, 557, -3*w^3 + 6*w^2 + 9*w - 10], [557, 557, 3*w^3 - 6*w^2 - 9*w - 1], [571, 571, 4*w^3 - 4*w^2 - 17*w - 6], [571, 571, -2*w^3 + 6*w^2 + 3*w - 10], [571, 571, 4*w^3 - 5*w^2 - 18*w + 3], [571, 571, -3*w^3 + 7*w^2 + 9*w - 5], [587, 587, 3*w^3 - 3*w^2 - 14*w], [587, 587, w^3 - w^2 - 2*w - 4], [593, 593, -w^3 + 3*w^2 + 2*w - 10], [593, 593, -5*w^3 + 7*w^2 + 19*w - 4], [613, 613, 3*w^3 - 5*w^2 - 12*w - 4], [613, 613, -w^3 + 3*w^2 - 10], [631, 631, 4*w^3 - 8*w^2 - 13*w + 4], [631, 631, 3*w^3 - 4*w^2 - 15*w + 2], [631, 631, w^3 - 9*w - 1], [631, 631, 3*w^3 - 7*w^2 - 7*w + 9], [643, 643, 3*w^3 - 3*w^2 - 16*w - 2], [643, 643, w^3 - w^2 - 8*w], [647, 647, -w^3 + 4*w^2 + 2*w - 4], [647, 647, -3*w^2 + 4*w + 10], [673, 673, w^3 + 2*w^2 - 9*w - 8], [673, 673, -w^3 + 4*w^2 + 3*w - 7], [683, 683, 3*w^3 - 3*w^2 - 11*w - 2], [683, 683, 4*w^3 - 4*w^2 - 17*w - 5], [709, 709, -5*w^3 + 7*w^2 + 21*w + 1], [709, 709, -3*w^3 + 2*w^2 + 16*w + 4], [709, 709, 4*w^3 - 4*w^2 - 19*w - 2], [709, 709, -2*w^3 + 4*w^2 + 3*w - 4], [787, 787, 2*w^2 - w - 9], [787, 787, w^3 + w^2 - 7*w - 2], [811, 811, 4*w^3 - 7*w^2 - 11*w], [811, 811, 3*w^3 - 4*w^2 - 9*w - 1], [811, 811, -6*w^3 + 9*w^2 + 23*w - 5], [811, 811, 5*w^3 - 6*w^2 - 21*w - 2], [821, 821, -3*w^3 + 6*w^2 + 11*w - 2], [821, 821, 2*w^3 - 13*w - 5], [821, 821, -w^3 + 4*w^2 - w - 9], [821, 821, -w^3 + 3*w^2 + 5*w - 6], [841, 29, 2*w^3 - 2*w^2 - 12*w - 1], [857, 857, w^3 - 4*w^2 + 3*w + 6], [857, 857, -5*w^3 + 8*w^2 + 21*w - 3], [863, 863, -w^3 + 4*w^2 + w - 7], [863, 863, -w^3 + 4*w^2 + w - 6], [877, 877, -w^3 - w^2 + 8*w + 2], [877, 877, -w^3 + 3*w^2 + 4*w - 8], [883, 883, 4*w^3 - 7*w^2 - 14*w + 1], [883, 883, 3*w^3 - 6*w^2 - 8*w + 7], [929, 929, 3*w^3 - 5*w^2 - 12*w - 3], [929, 929, -w^3 + 3*w^2 - 9], [929, 929, 3*w - 5], [929, 929, 3*w^3 - 3*w^2 - 15*w + 2], [937, 937, w^3 - 2*w^2 - 6*w + 6], [937, 937, 2*w^3 - w^2 - 12*w], [941, 941, -w^3 + 4*w^2 + 2*w - 7], [941, 941, -4*w^3 + 6*w^2 + 13*w - 3], [941, 941, -5*w^3 + 7*w^2 + 19*w + 2], [941, 941, 3*w^2 - 4*w - 7], [953, 953, 3*w^3 - 5*w^2 - 12*w - 2], [953, 953, -w^3 + 3*w^2 - 8], [961, 31, 4*w^3 - 6*w^2 - 13*w - 2], [961, 31, 5*w^3 - 7*w^2 - 19*w + 3], [977, 977, -4*w^3 + 7*w^2 + 19*w - 6], [977, 977, -3*w^3 + 7*w^2 + 10*w - 6]]; primes := [ideal : I in primesArray]; heckePol := x^4 - 2*x^3 - 10*x^2 + 4*x + 12; K := NumberField(heckePol); heckeEigenvaluesArray := [e, -1/2*e^3 + 3/2*e^2 + 3*e - 1, -1/2*e^2 + e + 2, -1/2*e^2 + 2*e + 2, 1/2*e^3 - e^2 - 4*e + 2, -e + 5, e^2 - e - 6, 1/2*e^3 - 2*e^2 - 3*e + 6, -1/2*e^3 + 2*e^2 + 2*e - 4, -e^3 + 5/2*e^2 + 5*e - 7, -1, 3/2*e^2 - 3*e - 9, -e^3 + 2*e^2 + 6*e - 4, 3/2*e^3 - 5*e^2 - 9*e + 14, 1/2*e^3 - e^2 - 8*e + 4, 1/2*e^3 - 1/2*e^2 - 5*e - 3, -1/2*e^3 + 2*e^2 + 3*e - 6, e^3 - 5*e^2 - e + 20, 1/2*e^3 - 3*e^2 - 2*e + 8, -2*e + 12, -e^3 + 7/2*e^2 + 3*e - 9, -1/2*e^3 + 6*e + 2, 3/2*e^3 - 4*e^2 - 7*e + 8, -1/2*e^3 + 3/2*e^2 + 2*e - 1, 1/2*e^3 - e^2 - 6*e + 2, 1/2*e^2 - 3*e - 4, 1/2*e^3 - 3/2*e^2 - 2*e + 8, 2*e^3 - 13/2*e^2 - 11*e + 17, e^3 - 5/2*e^2 - 10*e + 2, -1/2*e^3 - e^2 + 8*e + 2, -3/2*e^3 + 7/2*e^2 + 8*e + 2, e^2 - 6*e - 12, -3*e^2 + 5*e + 12, e^3 - 5/2*e^2 - 8*e + 18, 2*e^3 - 4*e^2 - 16*e + 12, 3/2*e^3 - 9/2*e^2 - 5*e + 9, 3/2*e^3 - 3*e^2 - 9*e + 6, e^3 - 4*e^2 + 2*e + 14, e^3 - 5/2*e^2 - 6*e + 3, -3/2*e^3 + 6*e^2 + 5*e - 18, -3*e^2 + 10*e + 12, 1/2*e^3 - 9/2*e^2 + e + 12, 2*e^3 - 5*e^2 - 14*e + 12, e^3 - 2*e^2 - 13*e + 6, 1/2*e^2 + 2*e + 6, -e^3 + e^2 + 7*e + 12, -1/2*e^3 + 5/2*e^2 - 6*e - 10, -3/2*e^3 + 7*e^2 + 5*e - 22, -1/2*e^3 + 10*e + 6, 2*e^3 - 13/2*e^2 - 15*e + 12, 2*e^3 - 11/2*e^2 - 17*e + 21, -1/2*e^3 + e^2 + 5*e + 6, -1/2*e^3 + 5/2*e^2 + 8*e - 15, e^2 + 2*e - 6, -3/2*e^3 + 8*e^2 - 28, -1/2*e^3 + 3*e^2 - e - 4, -e^3 + 2*e^2 + 10*e - 12, -e^3 + 1/2*e^2 + 17*e, -1/2*e^3 - 3*e^2 + 8*e + 18, 4*e^2 - 10*e - 18, -5/2*e^3 + 8*e^2 + 12*e - 22, e^3 - 3*e^2 - 7*e + 2, 1/2*e^3 - e^2 + e + 2, -1/2*e^3 + 5/2*e^2 - 2*e + 2, 2*e^3 - 6*e^2 - 9*e + 24, -1/2*e^3 - 5/2*e^2 + 7*e + 18, -3/2*e^3 + 1/2*e^2 + 16*e - 3, -3/2*e^3 + 2*e^2 + 7*e + 24, 2*e^3 - 3*e^2 - 11*e - 4, -3/2*e^3 + 15/2*e^2 + e - 22, 2*e^3 - 4*e^2 - 15*e + 14, 5/2*e^3 - 17/2*e^2 - 16*e + 20, -9/2*e^2 + 4*e + 36, -e^3 + 7/2*e^2 + 5*e - 15, -3/2*e^3 + 13/2*e^2 + 5*e - 1, -1/2*e^3 + 7/2*e^2 - 5*e - 22, 3/2*e^3 - 9/2*e^2 - e + 6, -2*e^3 + 27*e, -9/2*e^3 + 13*e^2 + 26*e - 30, -e^3 + 15/2*e^2 - 8*e - 33, -1/2*e^3 - 1/2*e^2 + 13*e + 2, 7/2*e^3 - 8*e^2 - 34*e + 14, -2*e^3 + 8*e^2 + 4*e - 28, -1/2*e^3 + 1/2*e^2 + 11*e + 11, 4*e^3 - 9*e^2 - 29*e + 14, -3/2*e^3 + 3*e^2 + 6*e + 20, 3/2*e^3 - 2*e^2 - 15*e - 4, 2*e^3 - 6*e^2 - 14*e + 26, -3*e^3 + 10*e^2 + 16*e - 28, 4*e^3 - 21/2*e^2 - 26*e + 17, 3/2*e^3 - 1/2*e^2 - 17*e + 9, -3*e^3 + 7*e^2 + 20*e - 24, -5/2*e^3 + 11/2*e^2 + 20*e + 3, -5/2*e^3 + 19/2*e^2 + 9*e - 21, e^3 + 5/2*e^2 - 9*e - 27, 9/2*e^3 - 9*e^2 - 32*e + 12, -7/2*e^3 + 9*e^2 + 26*e - 12, -3*e^3 + 15/2*e^2 + 20*e - 3, -2*e^3 + 4*e^2 + 25*e - 4, -3*e^3 + 4*e^2 + 23*e + 8, 5/2*e^3 - 7*e^2 - 15*e + 8, -5/2*e^3 + 19/2*e^2 + 9*e - 28, -e^3 + 5*e^2 + 10*e - 34, e^3 + e^2 - 12*e, 1/2*e^3 - e^2 + 3*e - 18, 5/2*e^3 - 13/2*e^2 - 9*e - 4, e^3 - 7*e^2 - 2*e + 26, -e^3 + 5/2*e^2 + 7*e - 19, 2*e^3 - 9/2*e^2 - 18*e + 5, 2*e^3 - 11/2*e^2 - 10*e + 9, -3*e^3 + 25/2*e^2 + 12*e - 42, -2*e^3 - 1/2*e^2 + 27*e + 18, -3/2*e^3 + 2*e^2 + 13*e + 12, 1/2*e^3 - 6*e^2 + 8*e + 8, -3/2*e^3 + 2*e^2 + 16*e - 4, -3*e^3 + 9/2*e^2 + 23*e + 17, 7/2*e^3 - 25/2*e^2 - 13*e + 35, -2*e^3 + 13/2*e^2 + 19*e - 31, -2*e^2 + 7*e - 4, -e^3 + 11/2*e^2 + e - 10, -3/2*e^3 + 6*e^2 + e - 28, -3*e^3 + 19/2*e^2 + 12*e - 36, 5/2*e^3 - 13*e^2 - 8*e + 30, 1/2*e^3 + 2*e^2 - 18*e - 10, 2*e^3 - 8*e^2 + e + 20, 4*e^3 - 11*e^2 - 32*e + 30, -e^3 + 2*e^2 + 6*e - 18, 4*e^3 - 9*e^2 - 27*e + 8, -3*e^3 + 6*e^2 + 30*e - 10, -7/2*e^3 + 9*e^2 + 26*e - 40, -1/2*e^3 + 3/2*e^2 - 6*e - 10, -2*e^3 + 5*e^2 + 15*e - 22, 3*e^3 - 4*e^2 - 23*e - 10, -4*e^3 + 10*e^2 + 31*e - 22, 4*e^3 - 31/2*e^2 - 9*e + 56, 11/2*e^3 - 13*e^2 - 44*e + 14, 38, 1/2*e^3 + 1/2*e^2 - e - 27, 2*e^3 - 10*e^2 + 3*e + 30, -e^3 + 1/2*e^2 + 10*e - 12, 7/2*e^3 - 3/2*e^2 - 42*e - 6, 3/2*e^3 - 5/2*e^2 - 18*e - 13, 5*e^2 - 5*e - 48, 2*e^3 - 15*e - 24, -4*e^2 - e + 42, -3/2*e^3 + 15/2*e^2 + e - 6, -3/2*e^3 + 13/2*e^2 - 4*e - 34, -e^3 + 23/2*e^2 - 5*e - 46, -1/2*e^3 + 11/2*e^2 - 15*e - 7, 2*e^3 - 5*e^2 - 10*e - 10, -1/2*e^3 + e^2 + 16*e - 12, -5/2*e^3 + 11/2*e^2 + 31*e + 6, -7/2*e^3 + 8*e^2 + 30*e - 24, -5/2*e^2 + 5*e + 45, -6*e^3 + 17*e^2 + 32*e - 46, 3*e^2 + 4*e - 22, -2*e^3 + 13*e^2 + 8*e - 60, -5*e^3 + 17*e^2 + 36*e - 48, -2*e^3 + 8*e^2 + 5*e - 24, -e^3 + 3/2*e^2 + 19*e - 9, 1/2*e^3 - e^2 - 3*e - 18, 1/2*e^3 - 2*e^2 - 6*e - 18, 1/2*e^3 + 7/2*e^2 - 17*e - 7, 7/2*e^3 - 13*e^2 - 17*e + 20, e^3 + 3*e^2 - 32*e - 18, 5/2*e^3 - 17/2*e^2 - 9*e + 15]; 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;