Yi-Hsiung HsuTZI-HONG CHIUEH2023-07-212023-07-212020-12-1424700010https://scholars.lib.ntu.edu.tw/handle/123456789/63401310 pages, 8 figuresThe evolution of cosmic perturbations in a two-component ultralight axionic universe is investigated. We present the first spectral computation of perturbations in multi-component universes. A particular case composed of light extreme axions and free massive particles offers a possibility for the formation of very high-redshift massive galaxies, which are typically required to host massive early quasars. Our computation retains the information of perturbed velocities for individual axion components, opening a new avenue for setting up initial conditions for future axion dark matter simulations.astro-ph.CO; astro-ph.COjournal article10.1103/PhysRevD.103.1035162-s2.0-85106345581http://arxiv.org/abs/2012.07602v2