EPR, Bell, and Quantum Locality

TL;DR

This paper argues that standard quantum mechanics can be considered local when properly formulated, challenging claims that no local theory can reproduce Bell inequality violations, and clarifies the role of counterfactual definiteness.

Contribution

It demonstrates that quantum mechanics, when correctly formulated, is compatible with locality, countering Maudlin's claim and clarifying the role of counterfactual definiteness in Bell's theorem.

Findings

Quantum mechanics can be formulated as a local theory.

Standard quantum mechanics reproduces Bell inequality violations.

Counterfactual definiteness is not essential for Bell's theorem.

Abstract

Maudlin has claimed that no local theory can reproduce the predictions of standard quantum mechanics that violate Bell's inequality for Bohm's version (two spin-half particles in a singlet state) of the Einstein-Podolsky-Rosen problem. It is argued that, on the contrary, standard quantum mechanics itself is a counterexample to Maudlin's claim, because it is local in the appropriate sense (measurements at one place do not influence what occurs elsewhere there) when formulated using consistent principles in place of the inconsistent appeals to "measurement" found in current textbooks. This argument sheds light on the claim of Blaylock that counterfactual definiteness is an essential ingredient in derivations of Bell's inequality.