Products of elementary matrices and non-Euclidean principal ideal domains

Cossu, L.;Zanardo, P.;Zannier, U.

2018-01-01

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Abstract

A classical problem, originated by Cohn's 1966 paper [1], is to characterize the integral domains R satisfying the property: (GE(n)) "every invertible n x n matrix with entries in R is a product of elementary matrices". Cohn called these rings generalized Euclidean, since the classical Euclidean rings do satisfy (GE(n)) for every n > 0. Important results on algebraic number fields motivated a natural conjecture: a non-Euclidean principal ideal domain R does not satisfy (GE(n)) for some n > 0. We verify this conjecture for two important classes of non-Euclidean principal ideal domains: (1) the coordinate rings of special algebraic curves, among them the elliptic curves having only one rational point; (2) the non-Euclidean PID's constructed by a fixed procedure, described in Anderson's 1988 paper [2]. (C) 2018 Elsevier Inc. All rights reserved.