2026 Sue Geller Undergraduate Lecture 

 Abstract:  Sperner's lemma is a simple combinatorial result that is surprisingly powerful and useful---bringing together ideas in combinatorics, geometry, and topology while attracting interest from economists and game theorists. I'll explain why, show some old and new proofs, and present some recent generalizations with diverse applications.

 Bio of Francis Su:    Francis Su is the Benediktsson-Karwa Professor of Mathematics at Harvey Mudd College, a former president of the Mathematical Association of America, and a Fellow of the American Mathematical Society. In 2013, he received the Haimo Award, a nationwide teaching prize for college math faculty, and in 2018 he won the Halmos-Ford writing award. His research is in geometric combinatorics and applications to the social sciences, he has published many papers with undergraduates. His work has been featured in Quanta Magazine, Wired, and the New York Times. His book Mathematics for Human Flourishing (2020), winner of the 2021 Euler Book Prize, has been translated into 8 languages. It offers an inclusive vision of what math is, who it's for, and why anyone should learn it.