Klose, P.; Laine, M.; Procacci, S. (2022). Gravitational wave background from vacuum and thermal fluctuations during axion-like inflation. Journal of cosmology and astroparticle physics, 2022(12), 020. Institute of Physics Publishing IOP 10.1088/1475-7516/2022/12/020
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Klose_2022_J._Cosmol._Astropart._Phys._2022_020.pdf - Published Version Available under License Creative Commons: Attribution (CC-BY). Download (1MB) | Preview |
We revisit the framework of axion-like inflation in view of the possibility that the coupling of the inflaton to a non-Abelian topological charge density could lead to the generation of a rapidly thermalizing heat bath. Both dispersive (mass) and absorptive (friction) effects are included. For phenomenologically viable parameters, the system remains in a weak regime of warm inflation (thermal friction ≪ Hubble rate). For tensor perturbations we derive an interpolating formula that incorporates both vacuum and thermal production. The latter yields a model-independent frequency shape ∼ f03 in the LISA window, whose coefficient allows to measure the maximal shear viscosity of the thermal epoch. It is a challenge, however, to find models where the coefficient is large enough to be observable.
Item Type: |
Journal Article (Original Article) |
|---|---|
Division/Institute: |
08 Faculty of Science > Institute of Theoretical Physics 10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC) |
UniBE Contributor: |
Klose, Philipp Mauritz, Laine, Mikko Sakari, Procacci, Simona |
Subjects: |
500 Science > 530 Physics |
ISSN: |
1475-7516 |
Publisher: |
Institute of Physics Publishing IOP |
Language: |
English |
Submitter: |
Binia Marti |
Date Deposited: |
17 Mar 2023 14:43 |
Last Modified: |
19 Mar 2023 02:14 |
Publisher DOI: |
10.1088/1475-7516/2022/12/020 |
BORIS DOI: |
10.48350/179873 |
URI: |
https://boris.unibe.ch/id/eprint/179873 |
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