Quantum theories with local information flow

Abstract

Bell non-locality is a term that applies to specific modifications and interpretations of quantum mechanics. Yet, Bell's original 1964 theorem is often used to assert that unmodified quantum mechanics itself is non-local and that local realist interpretations are untenable. Motivated by Bell's original inequality, we identify four viable categories of quantum theories: local quantum mechanics, superdeterminism, non-local collapse quantum mechanics, and non-local hidden variable theories. These categories, however, are not restricted by Bell's definition of locality. In light of currently available no-go theorems, local and deterministic descriptions seem to have been overlooked, and one possible reason for that could be the conflation between Bell-locality and a broader principle of locality. We present examples of theories where a local flow of quantum information is possible, and assess whether current experimental proposals and an improved philosophy of science can contrast interpretations and distinguish between them.