Ghostbusters: unitarity and causality of non-equilibrium effective field theories
Abstract: For a non-equilibrium physical system defined along a closed time path (CTP), a key constraint is the so-called largest time equation, which is a consequence of unitarity and implies causality. In this paper, we present a simple proof that if the propagators of a non-equilibrium effective...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Springer Science and Business Media LLC
2020
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| Online Access: | https://hdl.handle.net/1721.1/126120 |
| _version_ | 1826196084960002048 |
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| author | Gao, Ping Glorioso, Paolo Liu, Hong |
| author2 | Massachusetts Institute of Technology. Center for Theoretical Physics |
| author_facet | Massachusetts Institute of Technology. Center for Theoretical Physics Gao, Ping Glorioso, Paolo Liu, Hong |
| author_sort | Gao, Ping |
| collection | MIT |
| description | Abstract: For a non-equilibrium physical system defined along a closed time path (CTP), a key constraint is the so-called largest time equation, which is a consequence of unitarity and implies causality. In this paper, we present a simple proof that if the propagators of a non-equilibrium effective action have the proper pole structure, the largest time equation is obeyed to all loop orders. Ghost fields and BRST symmetry are not needed. In particular, the arguments for the proof can also be used to show that if ghost fields are introduced, their contributions vanish. |
| first_indexed | 2024-09-23T10:20:17Z |
| format | Article |
| id | mit-1721.1/126120 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T10:20:17Z |
| publishDate | 2020 |
| publisher | Springer Science and Business Media LLC |
| record_format | dspace |
| spelling | mit-1721.1/1261202022-09-26T17:20:09Z Ghostbusters: unitarity and causality of non-equilibrium effective field theories Gao, Ping Glorioso, Paolo Liu, Hong Massachusetts Institute of Technology. Center for Theoretical Physics Abstract: For a non-equilibrium physical system defined along a closed time path (CTP), a key constraint is the so-called largest time equation, which is a consequence of unitarity and implies causality. In this paper, we present a simple proof that if the propagators of a non-equilibrium effective action have the proper pole structure, the largest time equation is obeyed to all loop orders. Ghost fields and BRST symmetry are not needed. In particular, the arguments for the proof can also be used to show that if ghost fields are introduced, their contributions vanish. U.S. Department of Energy, Office of Science, Office of High Energy Physics (Grant DE-SC0012567) 2020-07-09T20:39:36Z 2020-07-09T20:39:36Z 2020-03 2019-06 2020-06-26T13:17:53Z Article http://purl.org/eprint/type/JournalArticle 1029-8479 https://hdl.handle.net/1721.1/126120 Gao, Ping et al. "Ghostbusters: unitarity and causality of non-equilibrium effective field theories." Journal of High Energy Physics 2020, 3 (March 2020): 40 en http://dx.doi.org/10.1007/jhep03(2020)040 Journal of High Energy Physics Creative Commons Attribution https://creativecommons.org/licenses/by/4.0/ The Author(s) application/pdf Springer Science and Business Media LLC Springer Berlin Heidelberg |
| spellingShingle | Gao, Ping Glorioso, Paolo Liu, Hong Ghostbusters: unitarity and causality of non-equilibrium effective field theories |
| title | Ghostbusters: unitarity and causality of non-equilibrium effective field theories |
| title_full | Ghostbusters: unitarity and causality of non-equilibrium effective field theories |
| title_fullStr | Ghostbusters: unitarity and causality of non-equilibrium effective field theories |
| title_full_unstemmed | Ghostbusters: unitarity and causality of non-equilibrium effective field theories |
| title_short | Ghostbusters: unitarity and causality of non-equilibrium effective field theories |
| title_sort | ghostbusters unitarity and causality of non equilibrium effective field theories |
| url | https://hdl.handle.net/1721.1/126120 |
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