Toward more realistic mass functions for ultradense dark matter halos

Abstract

Ultradense dark matter halos (UDMHs) are high concentrations of dark matter, assumed to have formed deep in the radiation-dominated era from amplified primordial perturbations. In this work we improve the previous works for the calculation of UDMH abundance by elaborating on the formation process of these halos by including various physical and geometrical modifications in the analysis. In particular, we investigate the impact of angular momentum, dynamical friction and triaxial collapse on the predicted mass functions for UDMHs. We perform the calculations for four primordial power spectra with different amplified features that allow for primordial black hole and UDHM formation in wide and narrow mass ranges. We also apply this analysis in the context of two possible scenarios for dark matter: the single-component and the multi-component. We find that the abundance of UDMHs is prominently enhanced in the presence of these more realistic mass functions.