Three consequences of decompositional consistency

TL;DR

This paper explores how self-consistent decompositions in quantum measurement theory, incorporating internal decoherence and known pointer states, can resolve the measurement problem without collapse.

Contribution

It demonstrates that imposing consistency conditions on von Neumann decompositions allows for a measurement framework that avoids the collapse postulate.

Findings

Decompositions must include internal decohering environments.

Apparatus should have known pointer components and ready states.

The approach avoids the measurement problem in minimal quantum mechanics.

Abstract

Decompositions of the world into systems have typically been regarded as arbitrary extra-theoretical assumptions in discussions of quantum measurement. One can instead regard decompositions as part of the theory, and ask what conditions they must satisfy for self-consistency. It is shown that self-consistent decompositions that specify a measurement context (i.e. von Neumann decompositions) must represent apparatus as containing internal decohering environments and as having known pointer components and ready states. Under these circumstances a von Neumann decomposition can function as a component of the ready state of the observer. Minimal no-collapse quantum mechanics supplemented by these consistency requirements on von Neumann decompositions avoids the measurement problem.