Evolution of perturbation and power spectrum in a two-component
  ultralight axionic universe
  The 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.
