We prove that van Hoeij’s original algorithm to factor univariate polynomials over the rationals runs in polynomial time, as well as natural variants. In particular, our approach also yields polynomial time complexity results for bivariate polynomials over a finite field.
Let be an abelian extension of -adic fields, and let denote the valuation ring of . We study ideals of the valuation ring of as integral representations of the Galois group . Assuming is absolutely unramified we use techniques from the theory of factorisability to investigate which ideals are isomorphic to an -order in the group algebra . We obtain several general and also explicit new results.
Let H be a Krull monoid with infinite class group and such that each divisor class of H contains a prime divisor. We show that for each finite set L of integers ≥2 there exists some h ∈ H such that the following are equivalent: (i) h has a representation for some irreducible elements , (ii) k ∈ L.
Dans cet article, nous déterminons et classifions toutes les extensions cycliques de degré de corps de nombres -rationnels contenant une racine primitive -ième de l’unité. (Cette notion est plus générale que celle de -régularité étudiée dans un travail antérieur).
Let be a number field containing, for some prime , the -th roots of unity. Let be a Kummer extension of degree of characterized by its modulus and its norm group. Let be the compositum of degree extensions of of conductor dividing . Using the vector-space structure of , we suggest a modification of the rnfkummer function of PARI/GP which brings the complexity of the computation of an equation of over from exponential to linear.