Simulation of a binary boson star merger

Author: Frans Pretorius, Department of Physics, Princeton University, specialist in numerical solution of the field equations of Einstein for gravity. The non-linearity and complexity of Einstein's equations make it challenging to solve even numerically, and some portion of his time is spent designing algorithms to efficiently solve the equations in parallel on large computer clusters, and software to manipulate and visualize the simulation results.

The video shows a binary boson star merger. Technically a boson star is a spherically symmetric static solutions of Einsteins field equation coupled to a scalar field (when they are free of singularities, otherwise they are black holes). Until today there is no observational evidence for the existence of a boson star. In fact, they are made of scalar elementary particles, and none has been discovered yet. Boson stars are hypothetical candidates for supermassive objects at the center of galaxies. In fact, for the supermassive object at the center of our own galaxy, evidence points towards a black hole, but the possibility that it is a boson or fermion star cannot be completely excluded so far.