Speaker
Heejoo Kim
(KIAS)
Description
The pre-inflationary axion dark matter scenario, with its uniform initial misalignment angle, is conventionally expected to yield smooth dark matter without substructure. We explore scenarios of pre-inflationary axion cosmology, where adiabatic temperature perturbations from inflation can source non-trivial axion density fluctuations through both the temperature-dependent QCD axion mass and anharmonic resonance with close-to-hilltop misalignment angles.
The former permits minicluster formation only in a narrow window; the latter produces O(0.1) density contrast at scales below the quantum Jeans momentum at matter–radiation equality, providing a clean initial condition for Schrodinger-Poisson simulations.