Gravitational Waves from Post-Collision of Fuzzy Dark Matter Solitons

TL;DR

This paper models gravitational waves emitted from the collision of fuzzy dark matter solitons using simulations of the Schrödinger-Poisson system, predicting detectable signals that can inform properties of dark matter particles.

Contribution

It introduces a new adimensional unit system and simulates FDM soliton collisions to predict gravitational wave signals, advancing understanding of FDM dynamics and observability.

Findings

GW frequencies are in the range of years$^{-1}$ for specific FDM masses

Simulations show GW signals depend on FDM particle mass

Future GW detection can constrain FDM properties

Abstract

According to the Schr\"odinger-Poisson (SP) equations, fuzzy dark matter (FDM) can form a stable equilibrium configuration, the so-called FDM soliton. The SP system can also determine the evolution of FDM solitons, such as head-on collision. In this paper, we first propose a new adimensional unit of length, time and mass. And then, we simulate the adimensional SP system with $\mathtt{PyUltraLight}$ to study the GWs from post-collision of FDM solitons when the linearized theory is valid and the GW back reaction on the evolution of FDM solitons is ignored. Finally, we find that the GWs from post-collisions have a frequency of (few ten-years)$^{-1}$ or (few years)$^{-1}$ when FDM mass is $m=10^{-18}\rm{eV}/c^2$ or $m=10^{-17}\rm{eV}/c^2$. Therefore, future detection of such GWs will constrain the property of FDM particle and solitons.