Factorization and irreducibility of composed products

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Kölsch, Lukas, Krompholz, Lucas, Kyureghyan, Gohar M.
Format: Preprint
Publié: 2024
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866917595712585728
author Kölsch, Lukas
Krompholz, Lucas
Kyureghyan, Gohar M.
author_facet Kölsch, Lukas
Krompholz, Lucas
Kyureghyan, Gohar M.
contents Brawley and Carlitz introduced diamond products of elements of finite fields and associated composed products of polynomials in 1987. Composed products yield a method to construct irreducible polynomials of large composite degrees from irreducible polynomials of lower degrees. We show that the composed product of two irreducible polynomials of degrees $m$ and $n$ is again irreducible if and only if $m$ and $n$ are coprime and the involved diamond product satisfies a special cancellation property, the so-called conjugate cancellation. This completes the characterization of irreducible composed products, considered in several previous papers. More generally, we give precise criteria when a diamond product satisfies conjugate cancellation. For diamond products defined via bivariate polynomials, we prove simple criteria that characterize when conjugate cancellation holds. We also provide efficient algorithms to check these criteria. We achieve stronger results as well as more efficient algorithms in the case that the polynomials are bilinear. Lastly, we consider possible constructions of normal elements using composed products and the methods we developed.
format Preprint
id arxiv_https___arxiv_org_abs_2402_14613
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Factorization and irreducibility of composed products
Kölsch, Lukas
Krompholz, Lucas
Kyureghyan, Gohar M.
Number Theory
Combinatorics
11T06, 12E20
Brawley and Carlitz introduced diamond products of elements of finite fields and associated composed products of polynomials in 1987. Composed products yield a method to construct irreducible polynomials of large composite degrees from irreducible polynomials of lower degrees. We show that the composed product of two irreducible polynomials of degrees $m$ and $n$ is again irreducible if and only if $m$ and $n$ are coprime and the involved diamond product satisfies a special cancellation property, the so-called conjugate cancellation. This completes the characterization of irreducible composed products, considered in several previous papers. More generally, we give precise criteria when a diamond product satisfies conjugate cancellation. For diamond products defined via bivariate polynomials, we prove simple criteria that characterize when conjugate cancellation holds. We also provide efficient algorithms to check these criteria. We achieve stronger results as well as more efficient algorithms in the case that the polynomials are bilinear. Lastly, we consider possible constructions of normal elements using composed products and the methods we developed.
title Factorization and irreducibility of composed products
topic Number Theory
Combinatorics
11T06, 12E20
url https://arxiv.org/abs/2402.14613