Certifying the absence of quantum nonlocality

TL;DR

This paper introduces a method to certify the absence of quantum nonlocality using extended nonlocal games, linking game performance to output unpredictability without third-party assumptions.

Contribution

It presents a novel approach to certify the absence of quantum nonlocality through extended nonlocal games, connecting game outcomes to unpredictability of outputs.

Findings

Extended nonlocal games can certify absence of quantum nonlocality.

Super-classical game performance guarantees output unpredictability.

The approach links nonlocality certification with unpredictability without third-party assumptions.

Abstract

Quantum nonlocality is an inherently non-classical feature of quantum mechanics and manifests itself through violation of Bell inequalities for nonlocal games. We show that in a fairly general setting, a simple extension of a nonlocal game can certify instead the absence of quantum nonlocality. Through contraposition, our result implies that a super-classical performance for such a game ensures that a player's output is unpredictable to the other player. Previously such output unpredictability was known with respect to a third party.