journal club on aspects of information, quantum theory, and gravity
16 Aug 2021
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 nonrelativistic detector models predict superluminal propagation of the field’s initial conditions. We draw parallels between this characteristic of detector models, stemming from their nonrelativistic dynamics, and Sorkin’s “impossible measurements on quantum fields” [2]. Based on these features, we discuss the validity of measurements in quantum field theory when performed with nonrelativistic particle detectors.