The APDE seminar on Monday, 5/10, will be given by Jeffrey Galkowski online via Zoom from **11.10am to 12.00pm PT (note the time change)**. To participate, email Georgios Moschidis (gmoschidis@berkeley.edu) or Federico Pasqualotto (fpasqualotto@berkeley.edu).

**Title:** Exponential accuracy for the method of perfectly matched layers.

**Abstract:** The method of perfectly matched layers (PML) is used to compute solutions to time harmonic wave scattering problems. This method can be seen as a numerical adaptation of the method of complex scaling in which the infinite exterior region is replaced by a Dirichlet condition on a finite region. In this talk, we recall the methods of complex scaling and PML and study the error produced by replacing the genuine scattering problem with the PML truncation. We show that this error decays exponentially as a function of the scaling angle, the scaling width, and the frequency. Based on joint work with E. Spence and D. Lafontaine.