BRANS-DICKE BOSON STARS - CONFIGURATIONS AND STABILITY THROUGH COSMICHISTORY

We make a detailed study of boson star configurations in Jordan-Brans- Dicke theory, studying both equilibrium properties and stability, and considering boson stars existing at different cosmic epochs. We show t hat these boson stars can be stable at any time of cosmic history, and that equilibrium stars are denser in the past. We analyse three diffe rent proposed mass functions for boson star systems. We study how the configurations depend on the value of the Jordan-Brans-Dicke coupling constant, and the properties of the stars under extreme values of the gravitational asymptotic constant. This last point allows us to extrac t conclusions about the stability behaviour concerning the scalar fiel d. Finally, other dynamical variables of interest, such as the radius, are also calculated. In this regard, it is shown that the radius corr esponding to the maximal boson star mass remains roughly the same duri ng cosmological evolution.