Gravitational production of heavy particles during and after inflation

Abstract We investigate the gravitational production of a scalar field χ with a mass exceeding the Hubble scale during inflation m χ ≳ H I , employing both analytical and numerical approaches. We demonstrate that the steepest descent method effectively captures the epochs and yields of gravitational...

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Main Authors: Davide Racco, Sarunas Verner, Wei Xue
Format: Article
Language:English
Published: SpringerOpen 2024-09-01
Series:Journal of High Energy Physics
Subjects:
Online Access:https://doi.org/10.1007/JHEP09(2024)129
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author Davide Racco
Sarunas Verner
Wei Xue
author_facet Davide Racco
Sarunas Verner
Wei Xue
author_sort Davide Racco
collection DOAJ
description Abstract We investigate the gravitational production of a scalar field χ with a mass exceeding the Hubble scale during inflation m χ ≳ H I , employing both analytical and numerical approaches. We demonstrate that the steepest descent method effectively captures the epochs and yields of gravitational production in a compact and simple analytical framework. These analytical results align with the numerical solutions of the field equation. Our study covers three spacetime backgrounds: de Sitter, power-law inflation, and the Starobinsky inflation model. Within these models, we identify two distinct phases of particle production: during and after inflation. During inflation, we derive an accurate analytic expression for the particle production rate, accounting for a varying Hubble rate. After inflation, the additional burst of particle production depends on the inflaton mass around its minimum. When this mass is smaller than the Hubble scale during inflation, H I , there is no significant extra production. However, if the inflaton mass is larger, post-inflation production becomes the dominant contribution. Furthermore, we explore the implications of gravitationally produced heavy fields for dark matter abundance, assuming their cosmological stability.
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spelling doaj-art-e097022ccee04ef8ab669fd27fa2def22024-12-08T12:15:16ZengSpringerOpenJournal of High Energy Physics1029-84792024-09-012024913610.1007/JHEP09(2024)129Gravitational production of heavy particles during and after inflationDavide Racco0Sarunas Verner1Wei Xue2Institut für Theoretische Physik, ETH ZürichInstitute for Fundamental Theory, Physics Department, University of FloridaInstitute for Fundamental Theory, Physics Department, University of FloridaAbstract We investigate the gravitational production of a scalar field χ with a mass exceeding the Hubble scale during inflation m χ ≳ H I , employing both analytical and numerical approaches. We demonstrate that the steepest descent method effectively captures the epochs and yields of gravitational production in a compact and simple analytical framework. These analytical results align with the numerical solutions of the field equation. Our study covers three spacetime backgrounds: de Sitter, power-law inflation, and the Starobinsky inflation model. Within these models, we identify two distinct phases of particle production: during and after inflation. During inflation, we derive an accurate analytic expression for the particle production rate, accounting for a varying Hubble rate. After inflation, the additional burst of particle production depends on the inflaton mass around its minimum. When this mass is smaller than the Hubble scale during inflation, H I , there is no significant extra production. However, if the inflaton mass is larger, post-inflation production becomes the dominant contribution. Furthermore, we explore the implications of gravitationally produced heavy fields for dark matter abundance, assuming their cosmological stability.https://doi.org/10.1007/JHEP09(2024)129Cosmological modelsCosmology of Theories BSMNonperturbative Effects
spellingShingle Davide Racco
Sarunas Verner
Wei Xue
Gravitational production of heavy particles during and after inflation
Journal of High Energy Physics
Cosmological models
Cosmology of Theories BSM
Nonperturbative Effects
title Gravitational production of heavy particles during and after inflation
title_full Gravitational production of heavy particles during and after inflation
title_fullStr Gravitational production of heavy particles during and after inflation
title_full_unstemmed Gravitational production of heavy particles during and after inflation
title_short Gravitational production of heavy particles during and after inflation
title_sort gravitational production of heavy particles during and after inflation
topic Cosmological models
Cosmology of Theories BSM
Nonperturbative Effects
url https://doi.org/10.1007/JHEP09(2024)129
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AT sarunasverner gravitationalproductionofheavyparticlesduringandafterinflation
AT weixue gravitationalproductionofheavyparticlesduringandafterinflation