Positivity from Cosmological Correlators
Abstract Effective field theories in flat space and in anti-de Sitter space are constrained by causality and unitarity, often in the form of positivity bounds. Similar bounds have been harder to demonstrate in cosmological backgrounds, where the roles of unitarity and causality are more obscure. For...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-04-01
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| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/JHEP04(2024)034 |
| _version_ | 1797220085428912128 |
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| author | Daniel Green Yiwen Huang Chia-Hsien Shen Daniel Baumann |
| author_facet | Daniel Green Yiwen Huang Chia-Hsien Shen Daniel Baumann |
| author_sort | Daniel Green |
| collection | DOAJ |
| description | Abstract Effective field theories in flat space and in anti-de Sitter space are constrained by causality and unitarity, often in the form of positivity bounds. Similar bounds have been harder to demonstrate in cosmological backgrounds, where the roles of unitarity and causality are more obscure. Fortunately, the expansion of the universe ensures that late-time cosmological correlators are effectively classical and the role of unitarity is played by classical statistical inequalities. For multi-field inflation, the resulting positivity constraints have long been known in terms of the Suyama-Yamaguchi inequality. In this paper, we demonstrate that similar statistical bounds imply nontrivial constraints for massive fields in the early universe. We show that any real anomalous dimensions for principal series fields in de Sitter space must be positive. We also derive a limit on the amplitude of particular oscillatory signals from inflation, including those arising in cosmological collider physics. Finally, we demonstrate that these constraints manifest themselves directly in the two-point statistics of matter and galaxies that will be measured in upcoming surveys. |
| first_indexed | 2024-04-24T12:43:56Z |
| format | Article |
| id | doaj.art-b3504feda65848b5b75bb5782f4b7f09 |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-04-24T12:43:56Z |
| publishDate | 2024-04-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-b3504feda65848b5b75bb5782f4b7f092024-04-07T11:06:14ZengSpringerOpenJournal of High Energy Physics1029-84792024-04-012024413010.1007/JHEP04(2024)034Positivity from Cosmological CorrelatorsDaniel Green0Yiwen Huang1Chia-Hsien Shen2Daniel Baumann3Department of Physics, University of California at San DiegoDepartment of Physics, University of California at San DiegoDepartment of Physics, University of California at San DiegoDepartment of Physics, National Taiwan UniversityAbstract Effective field theories in flat space and in anti-de Sitter space are constrained by causality and unitarity, often in the form of positivity bounds. Similar bounds have been harder to demonstrate in cosmological backgrounds, where the roles of unitarity and causality are more obscure. Fortunately, the expansion of the universe ensures that late-time cosmological correlators are effectively classical and the role of unitarity is played by classical statistical inequalities. For multi-field inflation, the resulting positivity constraints have long been known in terms of the Suyama-Yamaguchi inequality. In this paper, we demonstrate that similar statistical bounds imply nontrivial constraints for massive fields in the early universe. We show that any real anomalous dimensions for principal series fields in de Sitter space must be positive. We also derive a limit on the amplitude of particular oscillatory signals from inflation, including those arising in cosmological collider physics. Finally, we demonstrate that these constraints manifest themselves directly in the two-point statistics of matter and galaxies that will be measured in upcoming surveys.https://doi.org/10.1007/JHEP04(2024)034Cosmological modelsde Sitter spaceEarly Universe Particle PhysicsSpace-Time Symmetries |
| spellingShingle | Daniel Green Yiwen Huang Chia-Hsien Shen Daniel Baumann Positivity from Cosmological Correlators Journal of High Energy Physics Cosmological models de Sitter space Early Universe Particle Physics Space-Time Symmetries |
| title | Positivity from Cosmological Correlators |
| title_full | Positivity from Cosmological Correlators |
| title_fullStr | Positivity from Cosmological Correlators |
| title_full_unstemmed | Positivity from Cosmological Correlators |
| title_short | Positivity from Cosmological Correlators |
| title_sort | positivity from cosmological correlators |
| topic | Cosmological models de Sitter space Early Universe Particle Physics Space-Time Symmetries |
| url | https://doi.org/10.1007/JHEP04(2024)034 |
| work_keys_str_mv | AT danielgreen positivityfromcosmologicalcorrelators AT yiwenhuang positivityfromcosmologicalcorrelators AT chiahsienshen positivityfromcosmologicalcorrelators AT danielbaumann positivityfromcosmologicalcorrelators |