Kochen-Specker nonlocal hidden variables must include time-ordering to allow for measurement independence of several agents

TL;DR

This paper argues that nonlocal hidden variables in quantum mechanics require explicit time-ordering to maintain measurement independence across multiple agents in Bell-type experiments.

Contribution

It introduces a framework where contextual nonlocal hidden variables depend on time-ordering, ensuring consistency with measurement independence in multi-agent scenarios.

Findings

Time-ordering is necessary for nonlocal hidden variables to be consistent.

Contextual hidden variables must include measurement choices and their temporal sequence.

The framework applies to both spacelike and timelike configurations.

Abstract

We consider an ontology, in which contextual nonlocal hidden variables are stored as pre-existing possibilities in a repository outside space-time; and in which the context can be chosen ``freely'' (measurement independence) by each agent, both in spacelike and timelike configurations. We show that, in Bell-type experiments involving several agents, for this ontology to be consistent, the context must include not only the measurements that can be performed, but also the time ordering of the choices of different agents.