Computational Sciences and Engineering Conference (SIAM CSE15) in Salt Lake City, Utah)
Abstract. Absorbing layers are sometimes required to be impractically thick to offer an accurate Absorbing Boundary Condition (ABC) for the Helmholtz equation in heterogeneous media. In previous work [BR and Demanet, submitted, 2014], we used matrix probing to compress an ABC from a few exterior Helmholtz solves with random Dirichlet data. We now present an algorithm (nearly linear in the dimension of the matrix) for applying this compressed ABC using Partitioned Low Rank matrices.