On the Multiplicity of Zeroes of Polynomials with Quaternionic Coefficients

Abstract

Regular polynomials with quaternionic coefficients admit only isolated zeroes and spherical zeroes. In this paper we prove a factorization theorem for such polynomials. Specifically, we show that every regular polynomial can be written as a product of degree one binomials and special second degree polynomials with real coefficients. The degree one binomials are determined (but not uniquely) by the knowledge of the isolated zeroes of the original polynomial, while the second degree factors are uniquely determined by the spherical zeroes. We also show that the number of zeroes of a polynomial, counted with their multiplicity as defined in this paper, equals the degree of the polynomial. While some of these results are known in the general setting of an arbitrary division ring, our proofs are based on the theory of regular functions of a quaternionic variable, and as such they are elementary in nature and offer explicit constructions in the quaternionic setting.

Zeros of regular functions of quaternionic and octonionic variable: a division lemma and the camshaft effect

“…We obtain by different techniques some properties already known (cf. [11,[14][15][16]18,24]) and we extend others to the octonionic case. We find the exact relation existing between the zeros of two octonionic regular functions and those of their regular product.…”

“…2 for precise definitions) suggest the definition of the multiplicity of a zero of a regular function. Our definition is equivalent on quaternionic polynomials with the one given in [2] and in [16].…”

A Note on the Computation of All Zeros of Simple Quaternionic Polynomials

“…The approach chosen here leads to the following: The companion polynomial for p 2 is Proof. Let q 4 (z) = (z−r)(z−s) 2 = (z 2 −(r+s)z+rs) 2 . According to Lemma 6.2 we must have r + s = 0.…”

Corrigendum to “Rational rotation-minimizing frames on polynomial space curves of arbitrary degree” [J. Symbolic Comput. 45 (8) (2010) 844–856]

“…Now for t ∈ R, let A(t) = u(t) + v(t) i + p(t) j + q(t) k be monic, primitive, and of degree n ≥ 1. Then Theorem 2.1 of [6] shows that constants C 1 , C 2 , . .…”