Relativistic Time-of-Arrival Measurements: Predictions, Post-Selection and Causality Problems
We analyze time-of-arrival probability distributions for relativistic particles in the context of quantum field theory (QFT). We show that QFT leads to a unique prediction, modulo post-selection that incorporates properties of the apparatus into the initial state. We also show that an experimental d...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-11-01
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| Series: | Foundations |
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| Online Access: | https://www.mdpi.com/2673-9321/3/4/41 |
| _version_ | 1827574802893766656 |
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| author | Charis Anastopoulos Maria-Electra Plakitsi |
| author_facet | Charis Anastopoulos Maria-Electra Plakitsi |
| author_sort | Charis Anastopoulos |
| collection | DOAJ |
| description | We analyze time-of-arrival probability distributions for relativistic particles in the context of quantum field theory (QFT). We show that QFT leads to a unique prediction, modulo post-selection that incorporates properties of the apparatus into the initial state. We also show that an experimental distinction of different probability assignments is possible especially in near-field measurements. We also analyze causality in relativistic measurements. We consider a quantum state obtained by a spacetime-localized operation on the vacuum, and we show that detection probabilities are typically characterized by small transient non-causal terms. We explain that these terms originate from Feynman propagation of the initial operation, because the Feynman propagator does not vanish outside the light cone. We discuss possible ways to restore causality, and we argue that this may not be possible in measurement models that involve switching the field–apparatus coupling on and off. |
| first_indexed | 2024-03-08T20:46:12Z |
| format | Article |
| id | doaj.art-e5d3a9244f4049759b29a97d81047649 |
| institution | Directory Open Access Journal |
| issn | 2673-9321 |
| language | English |
| last_indexed | 2024-03-08T20:46:12Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Foundations |
| spelling | doaj.art-e5d3a9244f4049759b29a97d810476492023-12-22T14:09:52ZengMDPI AGFoundations2673-93212023-11-013472473710.3390/foundations3040041Relativistic Time-of-Arrival Measurements: Predictions, Post-Selection and Causality ProblemsCharis Anastopoulos0Maria-Electra Plakitsi1Department of Physics, University of Patras, 26500 Rio, GreeceDepartment of Electrical and Computing Engineering, University of Patras, 26500 Patras, GreeceWe analyze time-of-arrival probability distributions for relativistic particles in the context of quantum field theory (QFT). We show that QFT leads to a unique prediction, modulo post-selection that incorporates properties of the apparatus into the initial state. We also show that an experimental distinction of different probability assignments is possible especially in near-field measurements. We also analyze causality in relativistic measurements. We consider a quantum state obtained by a spacetime-localized operation on the vacuum, and we show that detection probabilities are typically characterized by small transient non-causal terms. We explain that these terms originate from Feynman propagation of the initial operation, because the Feynman propagator does not vanish outside the light cone. We discuss possible ways to restore causality, and we argue that this may not be possible in measurement models that involve switching the field–apparatus coupling on and off.https://www.mdpi.com/2673-9321/3/4/41quantum measurement theoryrelativistic quantum theorycausalitytime in quantum mechanics |
| spellingShingle | Charis Anastopoulos Maria-Electra Plakitsi Relativistic Time-of-Arrival Measurements: Predictions, Post-Selection and Causality Problems Foundations quantum measurement theory relativistic quantum theory causality time in quantum mechanics |
| title | Relativistic Time-of-Arrival Measurements: Predictions, Post-Selection and Causality Problems |
| title_full | Relativistic Time-of-Arrival Measurements: Predictions, Post-Selection and Causality Problems |
| title_fullStr | Relativistic Time-of-Arrival Measurements: Predictions, Post-Selection and Causality Problems |
| title_full_unstemmed | Relativistic Time-of-Arrival Measurements: Predictions, Post-Selection and Causality Problems |
| title_short | Relativistic Time-of-Arrival Measurements: Predictions, Post-Selection and Causality Problems |
| title_sort | relativistic time of arrival measurements predictions post selection and causality problems |
| topic | quantum measurement theory relativistic quantum theory causality time in quantum mechanics |
| url | https://www.mdpi.com/2673-9321/3/4/41 |
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