dorsal/arxiv
View SchemaNon locality and causal evolution in QFT
| Authors | Fabrizio Buscemi, Giuseppe Compagno |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0602221 |
| URL | https://arxiv.org/abs/quant-ph/0602221 |
| DOI | 10.1088/0953-4075/39/15/S16 |
| Journal | J.Phys.B.At.Mol.Opt.Phys.39:S695-S709,2006 |
Abstract
Non locality appearing in QFT during the free evolution of localized field states and in the Feynman propagator function is analyzed. It is shown to be connected to the initial non local properties present at the level of quantum states and then it does not imply a violation of Einstein's causality. Then it is investigated a simple QFT system with interaction, consisting of a classical source coupled linearly to a quantum scalar field, that is exactly solved. The expression for the time evolution of the state describing the system is given. The expectation value of any arbitrary ``good'' local observable, expressed as a function of the field operator and its space and time derivatives, is obtained explicitly at all order in the field-matter coupling constant. These expectation values have a source dependent part that is shown to be always causally retarded, while the non local contributions are source independent and related to the non local properties of zero point vacuum fluctuations.
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"abstract": "Non locality appearing in QFT during the free evolution of localized field\nstates and in the Feynman propagator function is analyzed. It is shown to be\nconnected to the initial non local properties present at the level of quantum\nstates and then it does not imply a violation of Einstein\u0027s causality. Then it\nis investigated a simple QFT system with interaction, consisting of a classical\nsource coupled linearly to a quantum scalar field, that is exactly solved. The\nexpression for the time evolution of the state describing the system is given.\nThe expectation value of any arbitrary ``good\u0027\u0027 local observable, expressed as\na function of the field operator and its space and time derivatives, is\nobtained explicitly at all order in the field-matter coupling constant. These\nexpectation values have a source dependent part that is shown to be always\ncausally retarded, while the non local contributions are source independent and\nrelated to the non local properties of zero point vacuum fluctuations.",
"arxiv_id": "quant-ph/0602221",
"authors": [
"Fabrizio Buscemi",
"Giuseppe Compagno"
],
"categories": [
"quant-ph"
],
"doi": "10.1088/0953-4075/39/15/S16",
"journal_ref": "J.Phys.B.At.Mol.Opt.Phys.39:S695-S709,2006",
"title": "Non locality and causal evolution in QFT",
"url": "https://arxiv.org/abs/quant-ph/0602221"
},
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