Nonlinear Gravitational Waves and Inhomogeneous Cosmologies

Preliminary results from a study of nonlinear gravitational waves in Minkowski space are presented. Both numerical and analytic techniques are used. A first order perturbation solution is obtained and used to benchmark the numerical damping and dispersion in the computer code. A set of numerical simulations is used to find and characterize the beginning of the nonlinear regime. Finally, a second order perturbation analysis is begun to model this transition to nonlinear behavior.