This event has been rescheduled for August 25.

We present a fast and accurate numerical method for the simulation of time domain scattering problem. Both acoustic and electromagnetic scattering problems are discussed. Nonreflecting boundary conditions (NRBCs) are used to truncate the problem. We first derive analytic expressions for the underlying convolution kernels which allow for a rapid and accurate evaluation of the convolution. To handle the nonlocality in space, we introduce the notion of boundary perturbation, which enables us to handle general bounded scatters by solving a sequence of wave equations in a regular domain. We propose an efficient spectral- Galerkin solver with Newmarks time integration for the truncated wave equation in the regular domain. Simulation results of spherical cloaking devices are given to show the efficiency and accuracy of the method.