Model for a Unified Quantum Description of Macroscopic and Microscopic Systems

摘要

A unified derivation of the behaviour of all objects from the basic dynamics of the microscopic world is attempted through the discussion of a dynamical model in which linear superpositions of states describing systems localized in far apart spatial regions are naturally suppressed for macroscopic bodies. The dynamics of macro-objects is considered first, and a modification of the dynamics of these objects with respect to the standard one implied by quantum mechanics is carried out, keeping in mind the requirement of suppressing linear combinations of far apart localized states (as an example one can think of the elimination of states involving linear superpositions of different pointer positions of a measuring instrument). To satisfy the above requirement the dynamical equation must induce transitions from pure states to statistical mixtures. A way of obtaining this result is to add in the dynamical equation a term corresponding to some measurement process to the one describing the Hamiltonian evolution. (One is then naturally led to consider localization measurements.) It is postulated that also the microscopic objects are governed by a dynamical equation of the previously introduced type. The development is presented under the following headings: the evolution equation, many particle systems, the free particle, particle trajectories, numerical example and conclusions. (Atomindex citation 16:072621)