Conformally covarient field equations

Conformally covariant field equations are defined in an analogous manner to relativistically invariant field equations with non-zero mass. To obtain a meaningfull definition the fields are taken as Banach valued functions on the conformal closure of the Minkowski space. A standard conformal operator is a conformally covariant operator which is also a non-decomposable relativistically invariant operator in the sense of Naimark. The first and second order standard conformal operators and the corresponding differential equations are studied in detail