Rotating scalar field and formation of Bose stars

Abstract

We study numerical evolutions of an initial cloud of self-gravitating bosonic dark matter with finite angular momentum. It is demonstrated that the initial spinning scalar cloud can undergo a gravitational condensation to form a Bose star in the system. The results imply that the time for the gravitational condensation changes significantly in the presence of finite angular momentum. It also strongly depends on the attractive or repulsive nature of the self-interaction in the bosonic cloud. It is demonstrated that Bose stars formed in our study are not having any significant rotation as all the vorticity after the gravitational condensation resides in the regions outside the star. Further, we show that angular momentum and self-interactions in the cloud can significantly influence the density and radius of a Bose star. We also discuss our results and their consistency with the work carried out by the earlier researchers.