Causality and chance in relativistic quantum field theories

TL;DR

This paper reevaluates the concepts of causality in relativistic quantum field theories, arguing that local causality is unmotivated while microcausality remains essential for consistency.

Contribution

It challenges traditional notions of local causality in relativistic quantum theories and clarifies the role of microcausality as a sufficient condition for consistency.

Findings

Local causality is unmotivated in relativistic quantum field theories.

Microcausality is necessary for the consistent application of these theories.

Reevaluation of causality principles in quantum field theory context.

Abstract

Bell appealed to the theory of relativity in formulating his principle of local causality. But he maintained that quantum field theories do not conform to that principle, even when their field equations are relativistically covariant and their observable algebras satisfy a relativistically motivated microcausality condition. A pragmatist view of quantum theory and an interventionist approach to causation prompt the reevaluation of local causality and microcausality. Local causality cannot be understood as a reasonable requirement on relativistic quantum field theories: it is unmotivated even if applicable to them. But microcausality emerges as a sufficient condition for the consistent application of a relativistic quantum field theory.