Jared Wunsch of Northwestern University : On propagation and diffraction

Posted by Cheng Ouyang , part of the Departmental Colloquium.

At

Sept. 11, 2026, 3 p.m.

In

636 SEO

Abstract

The principle of geometric optics in the theory of light waves and the correspondence principle of quantum mechanics are two (related) heuristics saying that in an appropriate limit, the propagation of waves should occur along particle trajectories of classical mechanics. There are many beautiful theorems substantiating these heuristics. It is also the case, though, that when singularities arise in the medium of propagation, the heuristics need to be enriched to account for the phenomenon of diffraction, in which waves propagate where particles cannot. I will describe some propagation and diffraction theorems in various contexts, as well as some recently obtained corollaries involving trace formulae, spectral asymptotics, and scattering resonances.