We classify linear operators over the octonions and relate them to linear equations
with octonionic coefficients and octonionic variables. Along the way, we also classify
linear operators over the quaternions, and show how to relate quaternionic and
octonionic operators to real matrices. In each case, we construct an explicit
basis of linear operators that maps to the canonical (real) matrix basis; in
contrast to the complex case, these maps are surjective. Since higher-order
polynomials can be reduced to compositions of linear operators, our construction
implies that the ring of polynomials in one variable over the octonions is
isomorphic to the product of eight copies of the ring of real polynomials in eight
variables.
Keywords
octonions, quaternions, division algebras, linear
operators, linear equations