# Causality and quantum theory

## TL;DR

This paper explores the nature of causality in quantum theory, critiques existing interpretations, and proposes that classical causality may emerge from quantum systems with a spacetime structure arising from algebraic observables.

## Contribution

It introduces a novel perspective on how classical causality could emerge from quantum systems and analyzes the implications of superluminal causation on spacetime structure.

## Key findings

- Causal cone structure can emerge from quantum systems with superluminal causation.
- Classical causality may be an emergent symmetry not fundamental at the quantum level.
- Constructs a spacetime topology from the algebra of quantum observables.

## Abstract

We begin with a brief summary of issues encountered involving causality in quantum theory, placing careful emphasis on the assumptions involved in results such as the EPR paradox and Bell's inequality. We critique some solutions to the resulting paradox, including Rovelli's relational quantum mechanics and the many-worlds interpretation. We then discuss how a spacetime manifold could come about on the classical level out of a quantum system, by constructing a space with a topology out of the algebra of observables, and show that even with an hypothesis of superluminal causation enforcing consistent measurements of entangled states, a causal cone structure arises on the classical level. Finally, we discuss the possibility that causality as understood in classical relativistic physics may be an emergent symmetry which does not hold on the quantum level.