The open effective field theory of inflation
Abstract In our quest to understand the generation of cosmological perturbations, we face two serious obstacles: we do not have direct information about the environment experienced by primordial perturbations during inflation, and our observables are practically limited to correlators of massless fi...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-10-01
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| Series: | Journal of High Energy Physics |
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| Online Access: | https://doi.org/10.1007/JHEP10(2024)248 |
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| author | Santiago Agüí Salcedo Thomas Colas Enrico Pajer |
| author_facet | Santiago Agüí Salcedo Thomas Colas Enrico Pajer |
| author_sort | Santiago Agüí Salcedo |
| collection | DOAJ |
| description | Abstract In our quest to understand the generation of cosmological perturbations, we face two serious obstacles: we do not have direct information about the environment experienced by primordial perturbations during inflation, and our observables are practically limited to correlators of massless fields, heavier fields and derivatives decaying exponentially in the number of e-foldings. The flexible and general framework of open systems has been developed precisely to face similar challenges. Building on previous work, we develop a Schwinger-Keldysh path integral description for an open effective field theory of inflation, describing the possibly dissipative and non-unitary evolution of the Goldstone boson of time translations interacting with an unspecified environment, under the key assumption of locality in space and time. Working in the decoupling limit, we study the linear and interacting theory in de Sitter and derive predictions for the power spectrum and bispectrum that depend on a finite number of effective couplings organised in a derivative expansion. The smoking gun of interactions with the environment is an enhanced but finite bispectrum close to the folded kinematical limit. We demonstrate the generality of our approach by matching our open effective theory to an explicit model. Our construction provides a standard model to simultaneously study phenomenological predictions as well as quantum information aspects of the inflationary dynamics. |
| format | Article |
| id | doaj-art-e39580ac1bda491fbaa50429fda2b775 |
| institution | OA Journals |
| issn | 1029-8479 |
| language | English |
| publishDate | 2024-10-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj-art-e39580ac1bda491fbaa50429fda2b7752025-08-20T02:31:17ZengSpringerOpenJournal of High Energy Physics1029-84792024-10-0120241018410.1007/JHEP10(2024)248The open effective field theory of inflationSantiago Agüí Salcedo0Thomas Colas1Enrico Pajer2Department of Applied Mathematics and Theoretical Physics, University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, University of CambridgeAbstract In our quest to understand the generation of cosmological perturbations, we face two serious obstacles: we do not have direct information about the environment experienced by primordial perturbations during inflation, and our observables are practically limited to correlators of massless fields, heavier fields and derivatives decaying exponentially in the number of e-foldings. The flexible and general framework of open systems has been developed precisely to face similar challenges. Building on previous work, we develop a Schwinger-Keldysh path integral description for an open effective field theory of inflation, describing the possibly dissipative and non-unitary evolution of the Goldstone boson of time translations interacting with an unspecified environment, under the key assumption of locality in space and time. Working in the decoupling limit, we study the linear and interacting theory in de Sitter and derive predictions for the power spectrum and bispectrum that depend on a finite number of effective couplings organised in a derivative expansion. The smoking gun of interactions with the environment is an enhanced but finite bispectrum close to the folded kinematical limit. We demonstrate the generality of our approach by matching our open effective theory to an explicit model. Our construction provides a standard model to simultaneously study phenomenological predictions as well as quantum information aspects of the inflationary dynamics.https://doi.org/10.1007/JHEP10(2024)248Cosmological modelsEffective Field Theoriesde Sitter spaceNon-Equilibrium Field Theory |
| spellingShingle | Santiago Agüí Salcedo Thomas Colas Enrico Pajer The open effective field theory of inflation Journal of High Energy Physics Cosmological models Effective Field Theories de Sitter space Non-Equilibrium Field Theory |
| title | The open effective field theory of inflation |
| title_full | The open effective field theory of inflation |
| title_fullStr | The open effective field theory of inflation |
| title_full_unstemmed | The open effective field theory of inflation |
| title_short | The open effective field theory of inflation |
| title_sort | open effective field theory of inflation |
| topic | Cosmological models Effective Field Theories de Sitter space Non-Equilibrium Field Theory |
| url | https://doi.org/10.1007/JHEP10(2024)248 |
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