Speaker
Description
The inner regions of dark matter halos exhibit a rich dynamical structure shaped by multi-streaming and phase-space mixing. In this talk, I will present our recent investigations into the multi-streaming region, characterized by the number of apocenter passages or the radial action of dark matter particles. Our results reveal a remarkable universality: when categorized by their number of apocenter passages, particles follow a distribution that aligns closely with the NFW profile (i.e., $\rho\propto r^{-1}$) in the innermost regions. This trend was observed to be established at an early stage of halo formation. I will also discuss how this behavior compares between cold dark matter (CDM) and warm dark matter (WDM) scenarios, shedding light on the impact of free-streaming on inner halo dynamics. These findings provide new insights into the fundamental processes governing halo structure and evolution.
