Abstract:  Proca stars, aka vector boson stars, are selfgravitating BoseEinstein condensates obtained as numerical stationary solutions of the Einstein(complex)Proca system. These solitonic objects can achieve a compactness comparable to that of black holes, thus yielding an example of a black hole mimicker, which, moreover, can be both stable and form dynamically from generic initial data by the mechanism of gravitational cooling. In a recent work we have explored the dynamical properties of these solitonic objects by performing both headon collisions and orbital mergers of equal mass Proca stars, using fully nonlinear numerical evolutions, and extracting the gravitational radiation.
