Analytical Emulator for the Baryon EoM inside the Fuzzy Dark Matter Soliton from Machine Learning

Abstract: An empirical baryon density profile can be included in the Schrödinger-Poisson (SP) equations to influence the fuzzy dark matter (FDM) soliton formation. However, to probe the effects of baryon on the other dynamical evolutions of the FDM soliton, its equation of motion (EoM) inside the corresponding FDM soliton is needed. In this paper, given an empirical baryon density profile, we first provide the cylinderical symmetric FDM soliton solution about the FDM density and the total potential of FDM and baryon. Then, we build an analytical baryon EoM from the obtained FDM density and total potential by machine learning. Finally, we check that this baryon EoM works as well as an empirical baryon density profile for the FDM soliton formation, with the fractional errors $\lesssim0.04$. It should also work well for some other simple FDM soliton evolutions.