1210.2988 (Adan Cabello)

A simple explanation of the quantum violation of a fundamental
inequality    [PDF]

Adan Cabello

We show that the maximum quantum violation of the simplest noncontextuality inequality is exactly the maximum value satisfying the following condition: The sum of probabilities of pairwise exclusive events cannot be higher than 1. We call this condition "global exclusive disjunction," since its power shows up when it is applied to global events resulting from enlarged scenarios in which the events in the inequality are considered jointly with other events. We identify scenarios in which this condition singles out quantum contextuality, and show that a recent proof excluding Popescu-Rohrlich nonlocal boxes follows from the maximum violation imposed by this condition to the simplest noncontextuality inequality.

View original: http://arxiv.org/abs/1210.2988