Linear perturbations in the oscillating scalar field dark matter model

An oscillating scalar field acts like cold dark matter in the expanding Universe. Perturbations of the scalar field are considered through a hierarchy of time and spatial scales generated by the H/m ratio. The scalar field reproduces the CDM scenarios on all relevant cosmological scales and throughout the evolution of the Universe from the beginning of the oscillations. An effective cutoff of short wavelength perturbations occurs in both matter-dominated and radiation-dominated epochs.