6 February 2023 5pm

Emily Adlam (University of Western Ontario)

On line seminar - to register, please send an email to silvia.debianchi@unimi.it

Is There Causation in Fundamental Physics?  New Insights from Process Matrices and Quantum Causal Modelling

Abstract

In this talk I will explore significance of the process matrix formalism and the quantum causal modelling programme for ongoing disputes about the role of causation in fundamental physics. I argue that the process matrix programme has correctly identified a notion of ‘causal order’ which plays an important role in fundamental physics, but this notion is weaker than the common-sense conception of causation because it does not involve asymmetry. I argue that causal order plays an important role in grounding more familiar causal phenomena. Then I apply these conclusions to the causal modelling programme within quantum foundations, arguing that since no-signalling quantum correlations cannot exhibit causal order, they should not be analysed using classical causal models. This resolves an open question about how to interpret fine-tuning in classical causal models of no-signalling correlations. Finally I observe that a quantum generalization of causal modelling can play a similar functional role to standard causal reasoning, but I emphasize that this functional characterisation does not entail that quantum causal models offer novel explanations of quantum processes.