Indistinguishability as nonlocality constraint

Abstract

A physical explanation for quantum bounds to nonlocality (Tsirelson's bound) is a fundamental problem that remains open, and one approach to explaining its origins is the so-called Exclusivity principle, relying on probabilistic assumptions shaping general probabilistic theories through sharp measurements and compatible (non-local) measurements. Information indistinguishability, presented here as indistinguishability of qubits and more general bits, may serve as an answer to the nonlocality conundrum, ultimately placing it as the origin to quantum limits. We connect indistinguishability to the exclusivity principle and show that indistinguishability leads to quantum bounds. With that, we suggest indistinguishability to be as fundamental as non-locality and relativistic causality for nonlocal realism.