BUBBLES IN BRANS-DICKE THEORY

Using the thin-wall approximation we develop a scheme to describe the evolution of true vacuum bubbles in Jordan-Brans-Dicke theory. We find four possible configurations depending on the surface energy density. The type of bubbles and the time of nucleation determines whether the bubbles recollapse or grow and ultimately expand with the speed of li ght, which in turn depends on the particle theory and the nucleation p rocess. The big bubbles problem of extended inflation is solved in the case where bubbles recollapse or where the nucleation radius is compa rable to the horizon size.