On (dis)agreement between different methods of calculation of the imaginary part of the effective action in expanding space-times
We consider two approaches to calculate imaginary parts of effective actions in expanding space-times. While the first approach uses Bogolyubov coefficients, the second one uses the functional integral or the Feynman propagator. In eternally expanding space-times these two approaches give different...
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| Format: | Article |
| Language: | English |
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Elsevier
2025-02-01
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| Series: | Physics Letters B |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0370269325000164 |
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| author | E.T. Akhmedov I.A. Belkovich D.V. Diakonov K.A. Kazarnovskii |
| author_facet | E.T. Akhmedov I.A. Belkovich D.V. Diakonov K.A. Kazarnovskii |
| author_sort | E.T. Akhmedov |
| collection | DOAJ |
| description | We consider two approaches to calculate imaginary parts of effective actions in expanding space-times. While the first approach uses Bogolyubov coefficients, the second one uses the functional integral or the Feynman propagator. In eternally expanding space-times these two approaches give different answers for the imaginary parts. The origin of the difference can be traced to the presence if the wave-functionals for the initial and final states in the functional integral. We show this explicitly on the example of the expanding Poincare patch of the de Sitter space-time. |
| format | Article |
| id | doaj-art-89a5d88efd224ba7b382ffa402e95e11 |
| institution | Kabale University |
| issn | 0370-2693 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Physics Letters B |
| spelling | doaj-art-89a5d88efd224ba7b382ffa402e95e112025-02-10T04:33:54ZengElsevierPhysics Letters B0370-26932025-02-01861139256On (dis)agreement between different methods of calculation of the imaginary part of the effective action in expanding space-timesE.T. Akhmedov0I.A. Belkovich1D.V. Diakonov2K.A. Kazarnovskii3Institutskii per, 9, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia; Academician Kurchatov Square, 1, NRC “Kurchatov Institute”, 123182, Moscow, RussiaInstitutskii per, 9, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, RussiaInstitutskii per, 9, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia; Bol'shoi Karetnyi per., 19, Institute for Information Transmission Problems, 127994, Moscow, Russia; Corresponding author.Institutskii per, 9, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, RussiaWe consider two approaches to calculate imaginary parts of effective actions in expanding space-times. While the first approach uses Bogolyubov coefficients, the second one uses the functional integral or the Feynman propagator. In eternally expanding space-times these two approaches give different answers for the imaginary parts. The origin of the difference can be traced to the presence if the wave-functionals for the initial and final states in the functional integral. We show this explicitly on the example of the expanding Poincare patch of the de Sitter space-time.http://www.sciencedirect.com/science/article/pii/S0370269325000164 |
| spellingShingle | E.T. Akhmedov I.A. Belkovich D.V. Diakonov K.A. Kazarnovskii On (dis)agreement between different methods of calculation of the imaginary part of the effective action in expanding space-times Physics Letters B |
| title | On (dis)agreement between different methods of calculation of the imaginary part of the effective action in expanding space-times |
| title_full | On (dis)agreement between different methods of calculation of the imaginary part of the effective action in expanding space-times |
| title_fullStr | On (dis)agreement between different methods of calculation of the imaginary part of the effective action in expanding space-times |
| title_full_unstemmed | On (dis)agreement between different methods of calculation of the imaginary part of the effective action in expanding space-times |
| title_short | On (dis)agreement between different methods of calculation of the imaginary part of the effective action in expanding space-times |
| title_sort | on dis agreement between different methods of calculation of the imaginary part of the effective action in expanding space times |
| url | http://www.sciencedirect.com/science/article/pii/S0370269325000164 |
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