Decoherent Histories Quantum Mechanics and Copenhagen Quantum Mechanics

TL;DR

This paper explores how decoherent histories quantum mechanics explains the emergence of classicality and measurement phenomena without postulating them, linking it to the Copenhagen interpretation.

Contribution

It demonstrates that classical worlds and measurement processes naturally arise from decoherent histories, providing a unifying explanation within quantum theory.

Findings

Classical worlds emerge from decoherent histories of quasiclassical variables.

Measurement and wave function collapse are explained without additional postulates.

Irreversibility is understood through decoherence processes.

Abstract

This paper discusses the relation between the decoherent histories approach to quantum mechanics that is based on coarse-grained decoherent histories of a closed system, and the approximate quantum mechanics of measured subsystems, as in the Copenhagen interpretation. We show how the a classical world used in such formulations is not to something to be postulated but rather explained by suitable sets of alternative histories of quasiclassical variables. We discuss the general definition of measurement, the collapse of the wave function, and irreversibility from the perspective of decoherent histories quantum theory..