A new approach to quantum measurement problem: cluster separability

TL;DR

This paper proposes a novel approach to the quantum measurement problem by reformulating cluster separability, introducing the concept of separation status, and emphasizing the role of detectors to address objectification in measurements.

Contribution

It extends Peres' proposal by reformulating cluster separability, defining separation status, and developing new rules for quantum measurement processes.

Findings

Separation status changes are kinematic, not dynamical.

Detectors are essential for measurement objectification.

A simplified registration model demonstrates the approach.

Abstract

The paper describes a solution to the problem of quantum measurement that has been proposed recently. The literal understanding of the basic rule of quantum mechanics on identical particles violates the cluster separation principle and so leads to difficulties. A proposal due to Peres of how such difficulties could be removed is reformulated and extended. Cluster separability leads to a locality requirement on observables and to the key notion of separation status. Separation status of a microsystem is shown to change in preparation and registration processes. The indispensability of detectors plays an important role. Changes of separation status are alterations of kinematic description rather than some parts of dynamical trajectories and so more radical than 'collapse of the wave function'. Textbook quantum mechanics does not provide any information of how separation status changes run, hence new rules must be formulated. This enables to satisfy the objectification requirement for registrations. To show how the ideas work, a simplified model of registration apparatus is constructed.