High-Order Multigrid-Reduction-In-Time for Linear Hyperbolic PDEs

Ben Ong, Michigan Technological University
4/03, 2024 at 11:10AM-12:00PM in 939 Evans (for in-person talks) and https://berkeley.zoom.us/j/98667278310

Multigrid Reduction in Time (MGRIT) uses multigrid reduction techniques to enable temporal parallelism for solving time dependent PDEs. Although MGRIT converges rapidly for diffusion-dominated PDEs, the convergence for advection-dominated PDEs is slow, or even non-convergent. For a two-level scheme with a fine-grid and a coarse grid, it is known that the convergence of MGRIT depends in part on the choice of time-stepping operators on the fine and coarse grid. In this talk, I will give a brief overview to MGRIT, some existing attempts to accelerate convergence for advection-dominated PDEs, and a proposed family of coarse-grid operators to accelerate convergence. This work is a joint effort with Dr. Robert Falgout (Lawrence Livermore National Laboratory).