The Peccei-Quinn solution to the strong CP problem provides a motivated framework rich in cosmological consequence. Thermal axion production is unavoidable if there is a thermal bath at early times. Scattering and decay processes of bath particles can dump relativistic axions in the primordial plasma, and they can leave observable signatures in cosmological observables probing both the early and the late universe if produced with a significant abundance. We present recent and significant improvements for the calculation of the axion production rate for different scenarios and apply these results to predict the abundance of produced axions. Finally, we provide updated cosmological bounds on the QCD axion mass.
Cited by 1
Mavromatos et al., Axion effective potentials induced by heavy sterile fermions
Eur. Phys. J. C 83, 866 (2023) [Crossref]
Author / Affiliations: mappings to Contributors and OrganizationsSee all Organizations.
- 1 Università degli Studi di Padova / University of Padua [UNIPD]
- 2 INFN Sezione di Padova / INFN Padova Division [INFN Padova]
- Horizon 2020 (through Organization: European Commission [EC])
- Instituto Nazionale di Fisica Nucleare (INFN) (through Organization: Istituto Nazionale di Fisica Nucleare / National Institute for Nuclear Physics [INFN])
- Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR) (through Organization: Ministero dell'Istruzione, dell'Università e della Ricerca / Ministry of Education, Universities and Research [MIUR])
- Università degli Studi di Padova / University of Padua [UNIPD]