Speaker
Description
In the pre-inflationary scenario, axion dark matter is expected to be highly homogeneous, with perturbations sourced mainly by gravity. We study a recently proposed mechanism in which the axion field couples to the temperature fluctuations in the primordial plasma, analysing its interplay with gravitational perturbations. We show how these plasma-induced fluctuations are transferred to the axion field and follow their evolution, finding significantly larger overdensities than in the standard gravity-induced scenario. We further explore the interplay between this mechanism and large misalignment angles, showing how together they can induce the formation of axion miniclusters and impact the small-scale structure of axion dark matter. These results imply that the local density relevant for direct detection experiments may differ from standard expectations.
| Primary Abstract Topic | Theory: Axions and Wave-Like-DM |
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