Field and Charge Measurements in Quantum Electrodynamics

Robert S. Cohen, John J. Stachel

Donald Bowen

Niels Henrik David Bohr, L. Rosenfeld

A survey is given of the problem of measurability in quantum electrodynamics and it is shown that it is possible in principle, by the use of idealized measuring arrangements, to achieve full conformity with the interpretation of the formalism as regards the determination of field and charge quantities.

Claus Kiefer

It is shown how the programme of decoherence can be applied in the context of quantum field theory. To illustrate the role of gauge invariance, we first discuss the charge superselection rule in quantum electrodynamics in some detail. We then present an example where macroscopic electromagnetic fields are ``measured" through interaction with charges and thereby rendered classical.

R. Weinstein