The QCD axion is a good dark matter candidate. The observed dark matter abundance can arise from misalignment or defect mechanisms, which generically require an axion decay constant fₐ∼O(10¹¹) GeV (or higher). We introduce a new cosmological origin for axion dark matter, parametric resonance from oscillations of the Peccei-Quinn symmetry breaking field, that requires fₐ∼(10⁸-10¹¹) GeV. The axions may be warm enough to give deviations from cold dark matter in large scale structure.
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Co et al. (2018) studied this question.
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