Restoring Locality: The Heisenberg Picture as a Separable Description of Quantum Theory

TL;DR

This paper explains how the Heisenberg picture offers a separable, local description of quantum theory, reconciling it with local realism and clarifying the nature of locality in quantum mechanics.

Contribution

It introduces a novel perspective using the Heisenberg picture to restore locality in quantum theory, building on and extending prior work by Deutsch, Hayden, and Raymond-Robichaud.

Findings

Quantum theory can be understood as respecting local realism in the Heisenberg picture.

The concept of local branching clarifies how locality is maintained in quantum processes.

Recent advances extend the understanding of locality beyond earlier models.

Abstract

Local realism has been the subject of much discussion in modern physics, partly because our deepest theories of physics appear to contradict one another in regard to whether reality is local. According to general relativity, it is, as physical quantities (perceptible or not) in two spacelike separated regions cannot affect one another. Yet, in quantum theory, it has traditionally been thought that local realism cannot hold and that such effects do occur. This apparent discrepancy between the two theories is resolved by Everettian quantum theory, as first proven by Deutsch & Hayden (2000). In this paper, I will explain how local realism is respected in quantum theory and review the advances in our understanding of locality since Deutsch & Hayden's work, including the concept of local branching and the more general analysis by Raymond-Robichaud (2021)