## Events

### Public Lecture by Francis Bonahon, Headley Distinguished Visitor-in-Residence

Title: "Curvature: Mountain Passes and Summits, Soap Films, and the Internet". Francis Bonahon, Professor of Mathematics from USC, will speak about how the mathematical idea of curvature of curves and surfaces has recently found surprising application to seemingly unrelated areas. No mathematical knowledge is needed for this talk. Francis Bonahon is a Headley Distinguished Visitor, sponsored by the Michael Morrill Fund, the Department of Mathematics and Dean of the College.

Abstract: The curvature of curves and surfaces in space is a classical mathematical concept, commonly taught in advanced calculus. We will stay away from ugly formulas, and focus instead on the intuitive significance of curvature. For instance, the top of a mountain and the bottom of a lake both have positive curvature, whereas the curvature is negative at a mountain pass. We will explain how the idea of curvature has recently found surprising applications to apparently unrelated areas, such as the analysis of traffic on the Internet. No mathematical knowledge is needed for this talk.

Bio: Francis Bonahon completed his doctoral education at the University of Paris 11 (Orsay) in 1979, 1985 or 1987, according to which degree you take into account. He was a permanent researcher at the french Centre National de la Recherche Scientifique from 1980 to 1986, and then moved to the University of Southern California where he has been ever since. He has an extensive research record in topology and geometry, preferably in low dimensions and with pretty pictures. He recently wrote an undergraduate textbook on low-dimensional geometry, published by the American Mathematical Society.

Supported by the Michael Morrill Fund, the Dean of the College Office and the Department of Mathematics.

Sponsored by Mathematics. Contact: Sue Jandro, x4360