  A well known method to solve the Polynomial Eigenvalue Problem (PEP) is via
linearization. That is, transforming the PEP into a generalized linear
eigenvalue problem with the same spectral information and solving such linear
problem with some of the eigenvalue algorithms available in the literature.
Linearizations of matrix polynomials are usually defined using unimodular
transformations. In this paper we establish a connection between the standard
definition of linearization for matrix polynomials introduced by Gohberg,
Lancaster and Rodman and the notion of polynomial system matrix introduced by
Rosenbrock. This connection gives new techniques to show that a matrix pencil
is a linearization of the corresponding matrix polynomial arising in a PEP.
