A numerical relativity study has investigated head-on collisions of boson stars, employing an initial data method inspired by the Bowen-York approach, commonly used to model binary black hole systems. This method allows for the incorporation of information from the early, post-Newtonian inspiral phase in binary coalescences, simplifying the modeling of these cosmic events. The research included testing the method on a single boson star with linear momentum, as well as simulations of head-on collisions between two boson stars and encounters between boson stars and black holes.

The results of this study are consistent with previous investigations, validating the effectiveness of the proposed initial data method. A key finding is that head-on collisions between boson stars emit a greater amount of energy in the form of gravitational waves compared to equivalent binary black hole collisions. This contrast suggests fundamental differences in the dynamics of gravitational wave emission between these compact objects.

Conversely, head-on collisions between a boson star and a black hole showed less gravitational radiation emission than their binary black hole counterparts. These differences in gravitational wave emission provide valuable insights for gravitational wave astrophysics and the characterization of exotic compact objects such as boson stars, which are candidates for dark matter.