The problem of identifying the system and the environment in the phenomenon of decoherence

OLIMPIA LOMBARDI; SEBASTIAN FORTIN; MARIO CASTAGNINO

EPSA Philosophy of Science

SPRINGER

Lugar: Dordrecht; Año: 2011; p. 161 - 174

The main purpose of this paper is to argue that decoherence is a relative phenomenon, better understood from a closed-system perspective according to which the split of a closed quantum system into an open subsystem and its environment is just a way of selecting a particular space of relevant observables of the whole closed system. In order to support this claim, we shall consider the results obtained in a natural generalization of the simple spin-bath model usually studied in the literature. Our main thesis will lead us to two corollaries. First, although the orthodox approach offers no general criterion for deciding where to place the ?cut? between system and environment, this not a real problem when one acknowledges the relative nature of decoherence. Second, the difference between energy dissipation and decoherence can be argued for on the basis of the relative nature of decoherence.