Scalar gravitation: A laboratory for numerical relativity

While not a correct physical theory, relativistic scalar gravitation provides a simple test site for developing many of the tools of numerical relativity. In contrast with general relativity, scalar gravitation allows gravitational waves to be generated in spherical symmetry. Hence one needs only one spatial dimension to try out methods of calculating wave emission and propagation. Using this theory, we have built a mean-field particle simulation scheme to study the dynamical behavior of collisionless matter in spherical symmetry. We find that we are able to calculate smooth and accurate wave forms, despite the stochastic representation of the matter source terms caused by sampling with a finite number of particles. A similar scheme should provide accurate wave forms in general relativity, provided sufficient computer resources are used.