SCALAR GRAVITATIONAL-WAVE FROM OPPENHEIMER-SNYDER COLLAPSE IN SCALAR-TENSOR THEORIES OF GRAVITY

Unlike general relativity, scalar-tensor theories of gravity predict s calar gravitational waves even from a spherically symmetric gravitatio nal collapse. We solve numerically the generation and propagation of t he scalar gravitational wave from a spherically symmetric and homogene ous dust collapse under the approximation that we can neglect the back reaction of the scalar wave on the space-time, and examine how the am plitude, characteristic frequency, and wave form of the observed scala r gravitational wave depend on the initial radius and mass of the dust and parameters contained in the theory. In the Brans-Dicke theory, th rough the observation of the scalar gravitational wave, it is possible to determine the initial radius and mass and a parameter contained in the theory. In the scalar-tensor theories, it would be possible to ge t the information of the first derivative of the coupling function con tained in the theory because the wave form of the scalar gravitational wave greatly depends on it.