A graph-separation theorem for quantum causal models
- Author(s)
- Jacques Pienaar, Caslav Brukner
- Abstract
A causal model is an abstract representation of a physical system as a directed acyclic graph (DAG), where the statistical dependencies are encoded using a graphical criterion called 'd-separation'. Recent work by Wood and Spekkens shows that causal models cannot, in general, provide a faithful representation of quantum systems. Since d-separation encodes a form of Reichenbach's common cause principle (RCCP), whose validity is questionable in quantum mechanics, we propose a generalized graph separation rule that does not assume the RCCP. We prove that the new rule faithfully captures the statistical dependencies between observables in a quantum network, encoded as a DAG, and reduces to d-separation in a classical limit.
- Organisation(s)
- Quantum Optics, Quantum Nanophysics and Quantum Information
- External organisation(s)
- Österreichische Akademie der Wissenschaften (ÖAW)
- Journal
- New Journal of Physics
- Volume
- 17
- No. of pages
- 25
- ISSN
- 1367-2630
- DOI
- https://doi.org/10.1088/1367-2630/17/7/073020
- Publication date
- 07-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103025 Quantum mechanics
- Keywords
- ASJC Scopus subject areas
- General Physics and Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/a27fb449-5063-4254-8b91-01012c5f03ac