Dark acoustic oscillations: imprints on the matter power spectrum and the halo mass function

摘要

Many non-minimal dark matter scenarios lead to oscillatory features in the matter power spectrum induced by interactions either within the dark sector or with particles from the standard model. Observing such dark acoustic oscillations would therefore be a major step towards understanding dark matter. We investigate what happens to oscillatory features during the process of non-linear structure formation. We show that at the level of the power spectrum, oscillations are smoothed out by non-linear mode coupling, gradually disappearing towards lower redshifts. In the halo mass function, however, the oscillatory features remain visible until the present epoch. As a consequence, dark acoustic oscillations could be detectable in observations that are either based on the halo mass function or on the high-redshift power spectrum. We investigate the effect of such features on different observables, namely the cluster mass function, the stellar-to-halo mass relation, and the Lyman alpha flux power spectrum. We find that oscillatory features remain visible in all of these observables, but they are very extended and of low amplitude, making it challenging to detect them as distinct features in the data.