We use linear algebraic methods to obtain general results about linear
operators on a space of polynomials that we apply to the operators associated
with a polynomial sequence by the monomiality property. We show that all such
operators are differential operators with polynomial coefficients of finite of
infinite order. We consider the monomiality operators associated with several
classes of polynomial sequences, such as Appell and Sheffer, and also
orthogonal polynomial sequences that include the Meixner, Krawtchouk, Laguerre,
Meixner-Pollaczek, and Hermite families.Comment: 28 page