FIELDS, OBSERVABLES AND GAUGE TRANSFORMATIONS .2.

We wish to study the construction of charge-carrying fields given the representation of the observable algebra in the sector of states of zero charge. It is shown that the set of those covariant sectors which can be obtained from the vacuum sector by acting with localized automorphisms" has the structure of a discrete Abelian group[Figure not available: see fulltext.]. An algebra of fields {Mathematical expression} can be defined on the Hilbert space of a representation π of the observable algebra {Mathematical expression} which contains each of the above sectors exactly once. The dual group of[Figure not available: see fulltext.] acts as a gauge group on {Mathematical expression} in such a way that {Mathematical expression} is the gauge invariant part of {Mathematical expression} is made up of Bose and Fermi fields and is determined uniquely by the commutation relations between spacelike separated fields. © 1969 Springer-Verlag."