The locality of quantum subsystems I

TL;DR

This paper examines the non-local nature of marginal probability distributions in entangled quantum systems across different interpretations, highlighting the dissociation between information flow and wavefunction structure.

Contribution

It provides a comparative analysis of how various interpretations address the locality of quantum subsystems and clarifies the distinction between information flow and wavefunction tensor structure.

Findings

Marginal distributions can be non-local without contradicting theory or experiment.

Different interpretations offer varied perspectives on the locality of quantum subsystems.

The dissociation between information flow and wavefunction structure is crucial for understanding quantum non-locality.

Abstract

Many of the contemporary formulations of quantum mechanics describe the marginal probability distributions of entangled many-body systems in a non-local way. Unlike the non-locality of joint distributions, the non-locality of marginal distributions is not forced by theory or experiment. This paper investigates the issue in the context of the Copenhagen, de Broglie-Bohm and sum-over-paths interpretations. A dissociation between information flow into quantum subsystems and the tensor product structure of wavefunctions is highlighted in connection to the problem.