Macroscopic Limit of Quantum Systems
Classical physics is approached from quantum mechanics in the macroscopic limit. The technical device to achieve this goal is the quantum version of the central limit theorem, derived for an observable at a given time and for the time-dependent expectation value of the coordinate. The emergence of t...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-08-01
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| Series: | Universe |
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| Online Access: | https://www.mdpi.com/2218-1997/7/9/315 |
| _version_ | 1797517064601075712 |
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| author | Janos Polonyi |
| author_facet | Janos Polonyi |
| author_sort | Janos Polonyi |
| collection | DOAJ |
| description | Classical physics is approached from quantum mechanics in the macroscopic limit. The technical device to achieve this goal is the quantum version of the central limit theorem, derived for an observable at a given time and for the time-dependent expectation value of the coordinate. The emergence of the classical trajectory can be followed for the average of an observable over a large set of independent microscopical systems, and the deterministic classical laws can be recovered in all practical purposes, owing to the largeness of Avogadro’s number. This result refers to the observed system without considering the measuring apparatus. The emergence of a classical trajectory is followed qualitatively in Wilson’s cloud chamber. |
| first_indexed | 2024-03-10T07:09:37Z |
| format | Article |
| id | doaj.art-63499c226fd64ad2a54991092649fd70 |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-03-10T07:09:37Z |
| publishDate | 2021-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj.art-63499c226fd64ad2a54991092649fd702023-11-22T15:32:45ZengMDPI AGUniverse2218-19972021-08-017931510.3390/universe7090315Macroscopic Limit of Quantum SystemsJanos Polonyi0The Department of Physics and Engineering, CNRS-IPHC, Strasbourg University, 23 rue du Loess BP28, CEDEX 02, 67037 Strasbourg, FranceClassical physics is approached from quantum mechanics in the macroscopic limit. The technical device to achieve this goal is the quantum version of the central limit theorem, derived for an observable at a given time and for the time-dependent expectation value of the coordinate. The emergence of the classical trajectory can be followed for the average of an observable over a large set of independent microscopical systems, and the deterministic classical laws can be recovered in all practical purposes, owing to the largeness of Avogadro’s number. This result refers to the observed system without considering the measuring apparatus. The emergence of a classical trajectory is followed qualitatively in Wilson’s cloud chamber.https://www.mdpi.com/2218-1997/7/9/315central limit theoremcollapse of the wave functioncloud chamber |
| spellingShingle | Janos Polonyi Macroscopic Limit of Quantum Systems Universe central limit theorem collapse of the wave function cloud chamber |
| title | Macroscopic Limit of Quantum Systems |
| title_full | Macroscopic Limit of Quantum Systems |
| title_fullStr | Macroscopic Limit of Quantum Systems |
| title_full_unstemmed | Macroscopic Limit of Quantum Systems |
| title_short | Macroscopic Limit of Quantum Systems |
| title_sort | macroscopic limit of quantum systems |
| topic | central limit theorem collapse of the wave function cloud chamber |
| url | https://www.mdpi.com/2218-1997/7/9/315 |
| work_keys_str_mv | AT janospolonyi macroscopiclimitofquantumsystems |