Explicit and unconditionally stable time-domain finite-element method with a more than “optimal” speedup

The “optimal” speedup of an explicit and unconditionally stable time-domain method is the ratio of the time step required by accuracy to the time step required by stability, without sacrificing accuracy. In this work, by significantly accelerating the explicit time-marching based revealing of the stable modes for any given time step, we demonstrate that it is feasible to achieve a more than “optimal” speedup.