DYNAMICAL EVOLUTION OF BOSON STARS - II - EXCITED-STATES AND SELF-INTERACTING FIELDS - ART. NO. 104004

The dynamical evolution of self-gravitating scalar field configuration s in numerical relativity is studied. The previous analysis on ground state boson stars of non-interacting fields is extended to excited sla tes and to fields with self-couplings. Self-couplings can significantl y change the physical dimensions of boson stars, making them much more astrophysically interesting (e.g., having mass of the order of 0.1 so lar mass). The stable (S) and unstable (U) branches of equilibrium con figurations of boson stars of self-interacting fields are studied, the ir behavior under perturbations and their quasi-normal oscillation fre quencies are determined and compared to the non-interacting case. Exci ted states of boson stars with and without self-couplings are studied and compared. Excited states also have equilibrium configurations with S and U branch structures: both branches are intrinsically unstable u nder a generic perturbation but have very different instability time s cales. We carry out a detailed study of the instability time scales of these configurations. It is found that highly excited states spontane ously decay through a cascade of intermediate states similar to atomic transitions. [S0556-2821(98)02220-6].