A histories perspective on characterizing quantum non-locality

Abstract

We introduce a framework for studying non-locality and contextuality inspired by the path integral formulation of quantum theory. We prove that the existence of a strongly positive joint quantum measure—the quantum analogue of a joint probability measure—on a set of experimental probabilities implies the Navascues–Pironio–Acin (NPA) condition ${{Q}^{1}}$ and is implied by the stronger NPA condition ${{Q}^{1+AB}}$ . A related condition is shown to be equivalent to ${{Q}^{1+AB}}$ .

Keywords

• non-locality
• contextuality
• NPA hierarchy
• quantum measure
• decoherence functional
• path integrals