Cosmology & Gravity Working Group — Massimiliano Lattanzi (Ferrara U and INFN, Italy)
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Europe/Stockholm
A5:1041
A5:1041
Description
Axions in cosmology
Axions can be produced in the early Universe through thermal or nonthermal processes. In the former case, they contribute to the cosmological energy budget as a hot dark matter component, while in the latter they could be the cold dark matter component. Moreover, if the breaking of the Peccei-Quinn symmetry happens during inflation, quantum fluctuations in the axion field will give rise to isocurvature perturbations. I will discuss constraints that can be put on axion properties from cosmological observations, mainly focusing on measurements of the anisotropies of the cosmic microwave background from the Planck satellite. I will also comment on the effect of theoretical uncertainties on estimates of axion parameters.