On Efficient Noncommutative Polynomial Factorization via Higman Linearization

Fuente: arXiv
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Main Authors: Arvind, V., Joglekar, Pushkar S.
Format: Preprint
Published: 2022
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author Arvind, V.
Joglekar, Pushkar S.
author_facet Arvind, V.
Joglekar, Pushkar S.
contents In this paper we study the problem of efficiently factorizing polynomials in the free noncommutative ring F of polynomials in noncommuting variables x1,x2,...,xn over the field F. We obtain the following result Given a noncommutative algebraic branching program of size s computing a noncommutative polynomial f in F as input, where F=Fq is a finite field, we give a randomized algorithm that runs in time polynomial in s, n and log q that computes a factorization of the polynomial f as a product f=f1f2...fr, where each fi is an irreducible polynomial that is output as a noncommutative algebraic branching program. The algorithm works by first transforming the given algebraic branching program computing f into a linear matrix L using Higman's linearization of polynomials. We then factorize the linear matrix L and recover the factorization of the polynomial f. We use basic elements from Cohn's theory of free ideals rings combined with Ronyai's randomized polynomial-time algorithm for computing invariant subspaces of a collection of matrices over finite fields.
format Preprint
id arxiv_https___arxiv_org_abs_2202_09883
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle On Efficient Noncommutative Polynomial Factorization via Higman Linearization
Arvind, V.
Joglekar, Pushkar S.
Computational Complexity
In this paper we study the problem of efficiently factorizing polynomials in the free noncommutative ring F of polynomials in noncommuting variables x1,x2,...,xn over the field F. We obtain the following result Given a noncommutative algebraic branching program of size s computing a noncommutative polynomial f in F as input, where F=Fq is a finite field, we give a randomized algorithm that runs in time polynomial in s, n and log q that computes a factorization of the polynomial f as a product f=f1f2...fr, where each fi is an irreducible polynomial that is output as a noncommutative algebraic branching program. The algorithm works by first transforming the given algebraic branching program computing f into a linear matrix L using Higman's linearization of polynomials. We then factorize the linear matrix L and recover the factorization of the polynomial f. We use basic elements from Cohn's theory of free ideals rings combined with Ronyai's randomized polynomial-time algorithm for computing invariant subspaces of a collection of matrices over finite fields.
title On Efficient Noncommutative Polynomial Factorization via Higman Linearization
topic Computational Complexity
url https://arxiv.org/abs/2202.09883