Eric Michielssen, who develops mathematical methods that enable engineers to simulate electromagnetic waves in large and complex systems, has been appointed the R. Bruce Sampsell Professor of Applied and Computational Mathematics, effective July 1, 2026.
He joined the Yale School of Engineering & Applied Science in January 2026 as chair of the Department of Applied and Computational Mathematics, where he is leading the development of the department's faculty and programs.
Mobile phones, radar, computer chips, and optical fibers all work by generating, guiding, or receiving electromagnetic fields and waves. Engineers designing these systems need to predict how those fields and waves will behave before anything is built. This requires solving what are known as "Maxwell's equations," which describe electric and magnetic fields. For large or intricate designs, the calculations can demand prohibitive amounts of computing time and memory.
Over three decades, Michielssen has developed algorithms that sharply reduce those demands while controlling numerical error. His work - at the interface of applied mathematics, computational science, and engineering - has made simulations possible at scales beyond the reach of earlier methods.
His contributions include "butterfly" algorithms, which compress the enormous arrays of numbers arising in these calculations, reducing the memory and computing time required. He has also developed methods for tracking electromagnetic waves over time and for rewriting equations in forms that computers can solve more efficiently.
Many of his former students and postdoctoral fellows now lead research groups of their own in academia and industry, in the U.S., Europe, and Asia.
A fellow of the Institute of Electrical and Electronics Engineers (IEEE), Michielssen has received the International Union of Radio Science's Isaac Koga Gold Medal and the Applied Computational Electromagnetics Society's CEM Award. His honors also include the IEEE Antennas and Propagation Society's Sergei A. Schelkunoff Award, Harrington-Mittra Award in Computational Electromagnetics, Chen-To Tai Distinguished Educator Award, and R. W. P. King Paper Award.
He has served as editor-in-chief of the International Journal of Numerical Modelling, as vice president of the Applied Computational Electromagnetics Society, and as chair of several international conferences in his field.
Before joining Yale, Michielssen spent 20 years at the University of Michigan, where he was the Louise Ganiard Johnson Professor of Engineering and professor of electrical engineering and computer science. He founded the Michigan Institute for Computational Discovery and Engineering and served as its inaugural director. He also was instrumental in creating the Michigan Institute for Data Science, led advanced research computing as associate vice president, and co-founded and co-directed the Precision Health initiative. He later served as associate dean for research in the College of Engineering.
Earlier in his career, he served on the faculty of the University of Illinois at Urbana-Champaign.
He earned his B.S. and M.S. from Katholieke Universiteit Leuven in Belgium and his Ph.D. from Illinois, all in electrical engineering.
