This special Physics department colloquium is scheduled for Monday afternoon at 3:30 pm in Room 137. Coffee and cookies are served at 3:15 pm in the same room. Anyone is welcome.

Physical Modeling of Sound – From Structure-Preservation to Inaudible Sources
Dr. Georg Essl, Assistant Professor, University of Michigan

How can we simulate the physics of sound quickly? This is the driving question for real-time simulation of physical sound. In this talk, I describe the development of structure-preserving ideas in the simulation of sound based on the history of transportation-based simulation methods called “waveguides.” Waveguides are based on the surprising discovery from the late 1970s that the one-dimensional linear wave equation can be simulated extremely efficiently. My own work raises the question of how we can generalize this particular discovery to higher dimensions and use the implied insights of retaining structural information of the solution space to create good numerical methods. In this talk I will also discuss a class of simple yet unusual forms of excitation patterns that fall in the class of non-radiating sources. We will discuss broad conditions that lead to such sources and constructive principles for how we can devise additional forms of “strange” excitations on wave equations that have the property of being either undetectable (inaudible) or that do not fit the standard expectations of radiation for typical sources.