CRITICAL-BEHAVIOR IN THE BRANS-DICKE THEORY OF GRAVITATION

The collapse of a massless scalar field in the Brans-Dicke theory of g ravitation is studied both under self-similar symmetry and under asymp totic flat boundary conditions. In the self-similar case, we find the critical exponent depends on omega, namely 1/2+/-1/2 root 2 omega+3. I n the case of the asymptotic Aat space-time, we use numerical method a nd find that the critical solution shows discrete selfsimilarity and t hat the critical exponent depends on omega, while the echoing paramete r depends weakly on it.