Evolution of coupled scalar perturbations through smooth reheating. I. Dissipative regime
| Autor: | Laine, M., Procacci, S., Rogelj, A. |
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| Rok vydání: | 2024 |
| Předmět: | |
| Zdroj: | JCAP 10 (2024) 040 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1475-7516/2024/10/040 |
| Popis: | If the inflaton is a heavy scalar field, it may equilibrate slower than some other degrees of freedom, e.g. non-Abelian gauge bosons. In this case, perturbations in the inflaton field and in a thermal plasma coexist from a given moment onwards. We derive a gauge-invariant set of three coupled equations governing the time evolution of such a system. Despite singular coefficients, a reliable numerical solution can be obtained for a long time period, starting from phase oscillations inside the Hubble horizon, and extending until acoustic oscillations in a radiation-dominated universe. Benchmarks are illustrated from a "weak regime", where perturbations have a quantum-mechanical origin but get dissipated by interactions with the plasma. Among applications of our formalism could be inhomogeneity-induced nucleations in post-inflationary phase transitions, and the production of scalar-induced gravitational waves. Comment: 34 pages. v2: clarifications added |
| Databáze: | arXiv |
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