On the Consistency of the Consistent Histories Approach to Quantum Mechanics

TL;DR

This paper critically examines the Consistent Histories approach to quantum mechanics, questioning its claims of resolving interpretational issues and analyzing its conceptual foundations and implications.

Contribution

It provides a critical analysis of the Consistent Histories formalism, highlighting ambiguities and challenging its claims of solving quantum interpretational problems.

Findings

Identifies vagueness in the interpretation of realms

Questions the link between measurements and histories

Challenges the evolutionary explanation of the framework

Abstract

The Consistent Histories (CH) formalism aims at a quantum mechanical framework which could be applied even to the universe as a whole. CH stresses the importance of histories for quantum mechanics, as opposed to measurements, and maintains that a satisfactory formulation of quantum mechanics allows one to assign probabilities to alternative histories of a quantum system. It further proposes that each realm, that is, each set of histories to which probabilities can be assigned, provides a valid quantum-mechanical account, but that different realms can be mutually incompatible. Finally, some of its proponents offer an "evolutionary" explanation of our existence in the universe and of our preference for quasiclassical descriptions of nature. The present work questions the validity of claims offered by CH proponents asserting that it solves many interpretational problems in quantum mechanics. In particular, we point out that the interpretation of the framework leaves vague two crucial points, namely, whether realms are fixed or chosen and the link between measurements and histories. Our claim is that by doing so, CH overlooks the main interpretational problems of quantum mechanics. Furthermore, we challenge the evolutionary explanation offered and we critically examine the proposed notion of a realm-dependent reality.