Quantum theory as a theory of interactions between macroscopic systems which can be described objectively

R. Fukuda

Models are presented as examples in order to illustrate the previously proposed theory of measurement in quantum mechanics [R. Fukuda, Phys. Rev. A 35, 8 (1987)]. It is based on the specific structure of the Hilbert space of the macroscopic system. It is shown that after the interaction of an object with a detector we have to prepare the exponential of the extensive operators to recover the interference which is lost in the measuring process.

Michael Springborg, Meijuan Zhou

L. Lanz, Bassano Vacchini, O. Melsheimer

We argue that the consistency problem between quantum theory and macroscopic objectivity must be placed inside a quantum description of macroscopic non-equilibrium systems. Resorting to thermodynamic concepts inside quantum field theory seems to be necessary.

Frank A. Wilczek

Tom Banks

I argue that conventional estimates of the criterion for classical behavior of a macroscopic body are incorrect, because they do not take into account the locality of interactions, which characterizes the behavior of all systems described approximately by local quantum field theory. Black holes are the only localized objects which do not have such a description. The deviations from classical behavior of a macroscopic body, except for those which can be described as classical uncertainties in the initial values of macroscopic variables,are {\it exponentially} small as a function of the volume of the macro-system in microscopic units.

Edgard Elbaz