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arXiv · 2102.03408

Relativistic causality in particle detector models: Faster-than-light signalling and "Impossible measurements"

José de Ramón·Maria Papageorgiou·Eduardo Martín-Martínez
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Abstract

We analyze potential violations of causality in Unruh DeWitt-type detector models in relativistic quantum information. We proceed by first studying the relation between faster-than-light signaling and the causal factorization of the dynamics for multiple detector-field interactions. We show in what way spatially extended non-relativistic detector models predict superluminal propagation of the field's initial conditions. We draw parallels between this characteristic of detector models, stemming from their non-relativistic dynamics, and Sorkin's "impossible measurements on quantum fields" arXiv:gr-qc/9302018. Based on these features, we discuss the validity of measurements in QFT when performed with non-relativistic particle detectors.

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José de Ramón, Maria Papageorgiou, Eduardo Martín-Martínez. 2021-02-05. Relativistic causality in particle detector models: Faster-than-light signalling and "Impossible measurements". https://doi.org/10.1103/physrevd.103.085002

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