Consistent Quantum Measurements

Abstract

In response to recent criticisms by Okon and Sudarsky, various aspects of the consistent histories (CH) resolution of the quantum measurement problem(s) are discussed using a simple Stern-Gerlach device, and compared with the alternative approaches to the measurement problem provided by spontaneous localization (GRW), Bohmian mechanics, many worlds, and standard (textbook) quantum mechanics. Among these CH is unique in solving the second measurement problem: inferring from the measurement outcome a property of the measured system at a time before the measurement took place, as is done routinely by experimental physicists. The main respect in which CH differs from other quantum interpretations is in allowing multiple stochastic descriptions of a given measurement situation, from which one (or more) can be selected on the basis of its utility. This requires abandoning a principle (termed unicity), central to classical physics, that at any instant of time there is only a single correct description of the world.

Version 2 has very minor changes. 17 pages

References in corpus (2)

• The New Quantum Logic
• Annotated Interview with a QBist in the Making

Cited by in corpus (6)

• The Meaning of the Wave Function: In Search of the Ontology of Quantum Mechanics
• Monogamy of quantum entanglement in time
• Quantum Superpositions Do Exist! But 'Quantum Physical Reality is different to Actuality' (Reply to Dieks and Griffiths)
• Reply to Comment [axXiv:1610.07734] by L. Vaidman on "Particle path through a nested Mach-Zehnder interferometer" [R. B. Griffiths, Phys. Rev. A 94 (2016) 032115]
• The Consistent Histories Formalism and the Measurement Problem
• Modelling of consciousness and interpretation of quantum mechanics