Bell Correlations and the Common Future

TL;DR

This paper explores how non-local correlations, like Bell correlations, could arise from causal structures involving closed space-time curves, challenging classical causality and proposing a quantum-inspired perspective.

Contribution

It introduces a novel causal framework involving closed space-time curves that can produce Bell correlations without multiple realities, blending quantum and relativistic ideas.

Findings

Closed space-time curves can generate non-local correlations.

Quantum entanglement can be modeled as a common cause in this framework.

The approach avoids the concept of multiple realities in explaining quantum phenomena.

Abstract

Reichenbach's principle states that in a causal structure, correlations of classical information can stem from a common cause in the common past or a direct influence from one of the events in correlation to the other. The difficulty of explaining Bell correlations through a mechanism in that spirit can be read as questioning either the principle or even its basis: causality. In the former case, the principle can be replaced by its quantum version, accepting as a common cause an entangled state, leaving the phenomenon as mysterious as ever on the classical level (on which, after all, it occurs). If, more radically, the causal structure is questioned in principle, closed space-time curves may become possible that, as is argued in the present note, can give rise to non-local correlations if to-be-correlated pieces of classical information meet in the common future --- which they need to if the correlation is to be detected in the first place. The result is a view resembling Brassard and Raymond-Robichaud's parallel-lives variant of Hermann's and Everett's relative-state formalism, avoiding "multiple realities."