Solvability by radicals from an algorithmic point of view

Any textbook on Galois theory contains a proof that a polynomial equation with solvable Galois group can be solved by radicals. From a practical point of view, we need to find suitable representations of the group and the roots of the polynomial. We first reduce the problem to that of cyclic extensions of prime degree and then work out the radicals, using the work of Girstmair. We give numerical examples of Abelian and non-Abelian solvable equations and apply the general framework to the construction of Hilbert Class fields of imaginary quadratic fields.

[1]  W. J. Thron,et al.  Encyclopedia of Mathematics and its Applications. , 1982 .

[2]  Harvey Cohn,et al.  Introduction to the construction of class fields , 1985 .

[3]  Gary L. Miller,et al.  Solvability by radicals is in polynomial time , 1983, STOC.

[4]  Ming-Deh A. Huang Factorization of Polynomials over Finite Fields and Decomposition of Primes in Algebraic Number Fields , 1991, J. Algorithms.

[5]  Henri Cohen,et al.  Heuristics on class groups of number fields , 1984 .

[6]  F. Morain,et al.  CONSTRUCTION OF HILBERT CLASS FIELDS OF IMAGINARY QUADRATIC FIELDS AND DIHEDRAL EQUATIONS MODULO p , 1989 .

[7]  Henri Cohen,et al.  A course in computational algebraic number theory , 1993, Graduate texts in mathematics.

[8]  Harvey Cohn,et al.  A classical invitation to algebraic numbers and class fields , 1978 .

[9]  Ming-Deh A. Huang Riemann hypothesis and finding roots over finite fields , 1985, STOC '85.

[10]  Gary L. Miller,et al.  Solvability by Radicals is in Polynomial Time , 1985, J. Comput. Syst. Sci..

[11]  G. Gras Extensions abéliennes non ramifiées de degré premier d'un corps quadratique , 1972 .

[12]  Vincenzo Acciaro,et al.  Computing automorphisms of abelian number fields , 1999, Math. Comput..

[13]  S. Kwon,et al.  Sur les corps résolubles de degré premier. , 1987 .

[14]  Ming-Deh A. Huang Generalized Riemann Hypothesis and Factoring Polynomials over Finite Fields , 1991, J. Algorithms.

[15]  A. Atkin,et al.  ELLIPTIC CURVES AND PRIMALITY PROVING , 1993 .

[16]  H. Lenstra,et al.  Algorithms in algebraic number theory , 1992, math/9204234.

[17]  Ming-Deh A. Huang Factorization of polynomials over finite fields and factorization of primes in algebraic number fields , 1984, STOC '84.