Kriging Interpolating Cosmic Velocity Field

Understand

[abridged] Volume-weighted statistics of large scale peculiar velocity is preferred by peculiar velocity cosmology, since it is free of uncertainties of galaxy density bias entangled in mass-weighted statistics.

• However, measuring the volume-weighted velocity statistics from galaxy (halo/simulation particle) velocity data is challenging.
• For the first time, we apply the Kriging interpolation to obtain the volume-weighted velocity field.
• Kriging is a minimum variance estimator.