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arXiv · 1711.10486

QCD Axion Dark Matter with a Small Decay Constant

Raymond T. Co·Lawrence J. Hall·Keisuke Harigaya
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Abstract

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 $f_a \sim \mathcal{O}(10^{11})$ 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 $f_a \sim (10^8 -10^{11})$ GeV. The axions may be warm enough to give deviations from cold dark matter in Large Scale Structure.

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Raymond T. Co, Lawrence J. Hall, Keisuke Harigaya. 2017-11-28. QCD Axion Dark Matter with a Small Decay Constant. https://doi.org/10.1103/physrevlett.120.211602

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