Simple explanation of the quantum limits of genuine $n$-body nonlocality

TL;DR

This paper explains the quantum limits of genuine n-body nonlocality using the exclusivity principle and a technical assumption, unifying bounds in contextuality and nonlocality.

Contribution

It demonstrates that the exclusivity principle and a technical assumption precisely determine quantum bounds for n-body nonlocality, linking two major research programs.

Findings

The exclusivity principle explains quantum bounds for n-body nonlocality.

A technical assumption is crucial for deriving these bounds.

The results unify understanding of contextuality and nonlocality bounds.

Abstract

Quantum $n$-body correlations cannot be explained with $(n-1)$-body nonlocality. However, this genuine $n$-body nonlocality cannot surpass certain bounds. Here we address the problem of identifying the principles responsible for these bounds. We show that, for any $n \ge 2$, the exclusivity principle, as derived from axioms about sharp measurements, and a technical assumption give the exact bounds predicted by quantum theory. This provides a unified explanation of the bounds of single-body contextuality and $n$-body nonlocality, and connects two programs towards understanding quantum theory.