CLASSICAL ANALOGS OF UNITARILY EQUIVALENT HAMILTON OPERATORS

A unitary transformation replaces the given description of a quantum s ystem by ail equivalent one. It is observed, however, that not all mem bers of a set of unitarily equivalent Hamilton operators are equally w ell suited for identifying the corresponding classical systems. A crit erion is proposed Sor recognizing the privileged representatives of th e set. A few explicit examples are reported that show the criterion at work.