Information-processing in theories constrained by no superluminal causation vs no superluminal signalling (2402.12446v1)
Abstract: Relativistic causality principles constrain information processing possibilities in space-time. No superluminal causation (NSC) and no superluminal signaling (NSS) are two such principles which, although related, are distinct. In this work we study the consequence of these principles by considering the tasks of generating non-classical correlations within two space-time configurations. Considering theories constrained by NSC, we show that the first task is impossible in any classical theory and the second is impossible in any (possibly non-classical) theory. However, we construct a protocol enabling non-classical correlations to be generated in both configurations in a theory restricted by the weaker NSS principle. To do so we exploit theories that allow an effect called jamming. In our realisation, non-communicating agents sharing classical resources and assisted by jamming, can generate PR-box correlations. Using this protocol the violation of NSC without violating NSS would be verifiable. We discuss the implications of these findings for the speed of generation of non-classical correlations. Our work offers insights into the differences in information processing power of theories constrained by NSC, NSS and other relativistic causality principles.
- Jamming nonlocal quantum correlations. Physical Review A 53, 3781–3784 (1996). link.
- The relativistic causality versus no-signaling paradigm for multi-party correlations. Nature Communications 10, 1701 (2019). link.
- General framework for cyclic and fine-tuned causal models and their compatibility with space-time. Physical Review A 106, 032204 (2022). link.
- Impossibility of superluminal signaling in Minkowski spacetime does not rule out causal loops. Physical Review Letters 129, 110401 (2022). link.
- A causal modelling analysis of bell scenarios in space-time: implications of jamming non-local correlations for relativistic causality principles (2023). link, eprint 2311.18465.
- Pearl, J. Causality: Models, reasoning, and inference. Second edition, Cambridge University Press (2009). link.
- Theory-independent limits on correlations from generalized Bayesian networks. New Journal of Physics 16, 113043 (2014). link.
- Quantum causal models. arXiv:1906.10726 (2020). link.
- Bell, J. S. Speakable and unspeakable in quantum mechanics. Cambridge University Press (1987).
- The lesson of causal discovery algorithms for quantum correlations: causal explanations of Bell-inequality violations require fine-tuning. New Journal of Physics 17, 033002 (2015). link.
- Causarum investigatio and the two Bell’s theorems of John Bell. arXiv:1503.06413 (2015). link.