Onthological models predictively inequivalent to quantum theory

TL;DR

This paper introduces a new ontological model that challenges previous claims by showing it can outperform quantum theory's predictions under certain assumptions, potentially leading to testable differences.

Contribution

It presents a novel ontological model that violates prior no-go theorems under a different free choice assumption, expanding the landscape of quantum foundations.

Findings

Model violates previous no-go theorems

Derives bounds on local averages for deterministic theories

Suggests possible experimental tests for the model

Abstract

Recently, it has been argued that no extension of quantum theory can have improved predictive power under a strong assumption of free choice of the experimental settings and validity of quantum mechanics. Here, under a different free choice assumption, we describe a model which violates this statement for almost all states of a bipartite two-level system, in a possibly experimentally testable way. From consistency with quantum mechanics and the nonsignaling principle, we derive a bound on the local averages for the family of deterministic ontological theories that our model belongs to.