Overlapping Localized Exponential Time Differencing Methods for Diffusion Problems
For researchers in numerical methods for PDEs, this work presents a rigorous convergence analysis of two localized exponential time differencing approaches, but the methods are incremental extensions of existing techniques.
The paper proposes two overlapping domain decomposition methods combined with exponential time differencing for solving diffusion equations, proving convergence and demonstrating performance through numerical experiments.
The paper is concerned with overlapping domain decomposition and exponential time differencing for the diffusion equation discretized in space by cell-centered finite differences. Two localized exponential time differencing methods are proposed to solve the fully discrete problem: the first method is based on Schwarz iteration applied at each time step and involves solving stationary problems in the subdomains at each iteration, while the second method is based on the Schwarz waveform relaxation algorithm in which time-dependent subdomain problems are solved at each iteration. The convergence of the associated iterative solutions to the corresponding fully discrete multidomain solution and to the exact semi-discrete solution is rigorously proved. Numerical experiments are carried out to confirm theoretical results and to compare the performance of the two methods.