Communication-constrained nonlocal correlations

TL;DR

This paper explores how communication constraints can distinguish quantum correlations from broader probabilistic theories by identifying fundamental operational principles that prevent unphysical behaviors.

Contribution

It extends communication-based principles to a wider class of tasks, deriving new constraints that reinforce communication as a key criterion for physical theories.

Findings

Identifies a broad family of implausible behaviors prevented by communication constraints

Develops a general information-theoretic framework for operational constraints

Reveals the fundamental role of communication in distinguishing quantum from non-quantum theories

Abstract

Identifying the physical grounds distinguishing quantum theory from broader probabilistic frameworks remains an open challenge. Communication-based proposals -- most notably the principles of impossibility of superluminal signaling and information causality (IC) -- highlight the role of communication in ruling out unphysical theories and offer an operational rationale on why quantum predictions prevail over these alternative models. Nevertheless, most such developments rely on communicating parts optimizing over specific tasks, such as communication complexity problems and random access codes (RAC). In this work, we systematically extend this communication-based approach. We characterize the class of communication tasks relevant for this context, and employ the general information-theoretic framework to derive new operational constraints preventing such unphysical behaviors. Remarkably, our results reveal a broad family of previously undetected implausible behaviors, independent of any particular encoding or decoding strategy, reinforcing the role of communication as a fundamental lens through which physically meaningful theories can be identified.