Title: The statistics of cosmlogical large scale peculiar velocity of dark matter particles and halos

Abstract:

I will focus on the statistiacal properties of cosmological large scale peculiar velocity of dark matter particles and halos.
(1) For dark matter particle velocity, we propose a peculiar velocity decomposition scheme to facilitate the RSD modeling and peculiar velocity reconstruction [1]. Then we measure  dark matter RSD-related statistics of the velocity eigenmodes through a set of N-body simulations [2], including  the velocity power spectra, correlation functions,  onepoint probability distribution functions, cumulants, and the damping functions describing the Finger of God effect.
(2) For dark matter halo velcoity, we measure the velocity bias of dark matter halos relative to dark matter particles in high-resolution N-body simulation. After correcting the sampling artifacts associated with our velocity sampling method (Nearest Particle method), we find that halos over a wide mass and redshift range whicht we have investigated show no velocity bias at k < 0.1h/Mpc [3].