The propagator matrix reloaded
The standard way to perform calculations for quantum field theories involves the S-matrix and the assumption that the theory is free at past and future infinity. However, this assumption may not hold for field theories in non-trivial backgrounds such as curved spacetimes or finite temperature. In fa...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SciPost
2023-03-01
|
| Series: | SciPost Physics Core |
| Online Access: | https://scipost.org/SciPostPhysCore.6.1.019 |
| _version_ | 1797860816108650496 |
|---|---|
| author | João F. Melo |
| author_facet | João F. Melo |
| author_sort | João F. Melo |
| collection | DOAJ |
| description | The standard way to perform calculations for quantum field theories involves the S-matrix and the assumption that the theory is free at past and future infinity. However, this assumption may not hold for field theories in non-trivial backgrounds such as curved spacetimes or finite temperature. In fact, even in the simple case of finite temperature Minkowski spacetime, there are a lot of misconceptions and confusion in the literature surrounding how to correctly take interactions into account when setting up the initial conditions. The objective of this work is to clear up these misconceptions and provide a clean and simple derivation of a formalism which includes interactions in the initial conditions and assesses whether or not it is legitimate to ignore them. The ultimate conclusion is that we cannot ignore them: quantum field theories at finite temperature are not free in the infinite past. |
| first_indexed | 2024-04-09T21:51:59Z |
| format | Article |
| id | doaj.art-5b4c250e00604c15863a503ec526231e |
| institution | Directory Open Access Journal |
| issn | 2666-9366 |
| language | English |
| last_indexed | 2024-04-09T21:51:59Z |
| publishDate | 2023-03-01 |
| publisher | SciPost |
| record_format | Article |
| series | SciPost Physics Core |
| spelling | doaj.art-5b4c250e00604c15863a503ec526231e2023-03-24T13:05:02ZengSciPostSciPost Physics Core2666-93662023-03-016101910.21468/SciPostPhysCore.6.1.019The propagator matrix reloadedJoão F. MeloThe standard way to perform calculations for quantum field theories involves the S-matrix and the assumption that the theory is free at past and future infinity. However, this assumption may not hold for field theories in non-trivial backgrounds such as curved spacetimes or finite temperature. In fact, even in the simple case of finite temperature Minkowski spacetime, there are a lot of misconceptions and confusion in the literature surrounding how to correctly take interactions into account when setting up the initial conditions. The objective of this work is to clear up these misconceptions and provide a clean and simple derivation of a formalism which includes interactions in the initial conditions and assesses whether or not it is legitimate to ignore them. The ultimate conclusion is that we cannot ignore them: quantum field theories at finite temperature are not free in the infinite past.https://scipost.org/SciPostPhysCore.6.1.019 |
| spellingShingle | João F. Melo The propagator matrix reloaded SciPost Physics Core |
| title | The propagator matrix reloaded |
| title_full | The propagator matrix reloaded |
| title_fullStr | The propagator matrix reloaded |
| title_full_unstemmed | The propagator matrix reloaded |
| title_short | The propagator matrix reloaded |
| title_sort | propagator matrix reloaded |
| url | https://scipost.org/SciPostPhysCore.6.1.019 |
| work_keys_str_mv | AT joaofmelo thepropagatormatrixreloaded AT joaofmelo propagatormatrixreloaded |