Collisions of Hedgehog Solitons in Vector Dark Matter

Dark matter makes up 84% of the matter in our universe, but we know very little about its underlying nature. In particular, the intrinsic spin and mass of the constituent particles are not known. In a Vector Dark Matter (VDM) model made of ultralight spin-1 particles, dark matter can be treated as a 3-component classical vector field. Such vector fields allow for “Hedgehog” soliton solutions: a spatially localized, stable wave configuration with a radially symmetric field configuration. I will report on our investigation of collisions of such hedgehog solitons using 3+1 dimensional numerical simulations of a multicomponent Schrodinger-Poisson system. Contrary to expectations, we found that the collisions do not result in the formation of a “Polarized” soliton (which is a lower energy state compared to a Hedgehog). Instead, we found that the objects tended to settle into two orbiting high-density regions. Time permitting, I will discuss potential implications of these results for the stability of hedgehog solitons, and the likelihood of forming different types of solitons in VDM, as well as their observational consequences.