Construction of fuzzy dark matter halos with arbitrary initial velocities

TL;DR

This paper develops a practical method to construct fuzzy dark matter halos with arbitrary initial velocities, enabling more flexible and controlled simulations of cosmic structures.

Contribution

It introduces a theoretical formula for initial global velocity in FDM halos and demonstrates how to adjust it for customized initial conditions.

Findings

Derived a formula linking initial velocity to interference of parity states

Validated the formula against simulation results

Provided a method to counteract and set initial velocities

Abstract

Cosmological simulations of fuzzy dark matter (FDM) are computationally expensive, and the resulting halos lack flexibility in parameter adjustments, such as virial mass, density profile, and global velocity. Previous studies have introduced a method for constructing FDM halos with predefined density profiles. In this study, we investigate the initial global velocity of these constructed halos and find that it is nonzero. We provide the theoretical formula for this velocity and illustrate that it arises from the interference between states of odd and even parity. Our calculated results closely match simulation outcomes. Additionally, we showcase how to counteract this velocity and create a halo with a customizable initial global velocity. Our study presents a practical method for adjusting the initial global velocity of halos in controlled FDM simulations, facilitating investigations into tidal effects, galaxy collisions, and other scenarios.