Particle production from oscillating scalar field and consistency of Boltzmann equation
Abstract Boltzmann equation plays important roles in particle cosmology in studying the evolution of distribution functions (also called as occupation numbers) of various particles. For the case of the decay of a scalar condensation ϕ into a pair of scalar particles (called χ), we point out that the...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2021-03-01
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| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/JHEP03(2021)296 |
| _version_ | 1818642792739504128 |
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| author | Takeo Moroi Wen Yin |
| author_facet | Takeo Moroi Wen Yin |
| author_sort | Takeo Moroi |
| collection | DOAJ |
| description | Abstract Boltzmann equation plays important roles in particle cosmology in studying the evolution of distribution functions (also called as occupation numbers) of various particles. For the case of the decay of a scalar condensation ϕ into a pair of scalar particles (called χ), we point out that the system may not be well described by the Boltzmann equation when the occupation number of χ becomes large even in the so-called narrow resonance regime. We study the particle production including the possible enhancement due to a large occupation number of the final state particle, known as the stimulated emission or the parametric resonance. Based on the quantum field theory (QFT), we derive a set of equations which directly govern the evolution of the distribution function of χ. Comparing the results of the QFT calculation and those from the Boltzmann equation, we find non-agreements in some cases. In particular, in the expanding Universe, the occupation number of χ based on the QFT may differ by many orders of magnitude from that from the Boltzmann equation. We also discuss a possible relation between the evolution equations based on the QFT and the Boltzmann equation. |
| first_indexed | 2024-12-16T23:48:42Z |
| format | Article |
| id | doaj.art-8725ca425cba4516a96663206a9f11f1 |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-12-16T23:48:42Z |
| publishDate | 2021-03-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-8725ca425cba4516a96663206a9f11f12022-12-21T22:11:25ZengSpringerOpenJournal of High Energy Physics1029-84792021-03-012021312210.1007/JHEP03(2021)296Particle production from oscillating scalar field and consistency of Boltzmann equationTakeo Moroi0Wen Yin1Department of Physics, University of TokyoDepartment of Physics, University of TokyoAbstract Boltzmann equation plays important roles in particle cosmology in studying the evolution of distribution functions (also called as occupation numbers) of various particles. For the case of the decay of a scalar condensation ϕ into a pair of scalar particles (called χ), we point out that the system may not be well described by the Boltzmann equation when the occupation number of χ becomes large even in the so-called narrow resonance regime. We study the particle production including the possible enhancement due to a large occupation number of the final state particle, known as the stimulated emission or the parametric resonance. Based on the quantum field theory (QFT), we derive a set of equations which directly govern the evolution of the distribution function of χ. Comparing the results of the QFT calculation and those from the Boltzmann equation, we find non-agreements in some cases. In particular, in the expanding Universe, the occupation number of χ based on the QFT may differ by many orders of magnitude from that from the Boltzmann equation. We also discuss a possible relation between the evolution equations based on the QFT and the Boltzmann equation.https://doi.org/10.1007/JHEP03(2021)296Beyond Standard ModelCosmology of Theories beyond the SM |
| spellingShingle | Takeo Moroi Wen Yin Particle production from oscillating scalar field and consistency of Boltzmann equation Journal of High Energy Physics Beyond Standard Model Cosmology of Theories beyond the SM |
| title | Particle production from oscillating scalar field and consistency of Boltzmann equation |
| title_full | Particle production from oscillating scalar field and consistency of Boltzmann equation |
| title_fullStr | Particle production from oscillating scalar field and consistency of Boltzmann equation |
| title_full_unstemmed | Particle production from oscillating scalar field and consistency of Boltzmann equation |
| title_short | Particle production from oscillating scalar field and consistency of Boltzmann equation |
| title_sort | particle production from oscillating scalar field and consistency of boltzmann equation |
| topic | Beyond Standard Model Cosmology of Theories beyond the SM |
| url | https://doi.org/10.1007/JHEP03(2021)296 |
| work_keys_str_mv | AT takeomoroi particleproductionfromoscillatingscalarfieldandconsistencyofboltzmannequation AT wenyin particleproductionfromoscillatingscalarfieldandconsistencyofboltzmannequation |