Non-linear dynamics of spinning bosonic stars part 1: formation
Presenting author: Fabrizio Di Giovanni
We perform fully non-linear numerical simulations of the Einstein-(complex, massive) Klein-Gordon and Einstein--(complex) Proca systems, to assess the formation of spinning bosonic stars. We firstly build constraint-solving initial data describing a dilute, axisymmetric spinning cloud of scalar/Proca bosons. We then evolve each model observing the gravitational collapse toward a spinning boson star, via the gravitational cooling mechanism. In the scalar case, during the relaxation to an equilibrium configuration, a non-axisymmetric instability always develops reshaping the energy density profile and ejecting angular momentum. In the Proca case, by contrast, no instability occurs and each evolution suggests the formation of a spinning Proca star. Our analysis suggests bosonic stars have different dynamical properties in the scalar/vector case, which we tentatively relate to their toroidal/spheroidal morphology.
Oral presentation: yes. Poster: no.