UBC Discrete Math Seminar: Stefan Steinerberger
Topic
How curved is a combinatorial graph?
Speakers
Details
Curvature is one of the fundamental ingredients in differential geometry. People are increasingly interested in whether it is possible to think of combinatorial graphs as manifolds and a number of different notions of curvature have been proposed. I will introduce some of the existing ideas and then propose a new notion based on a simple and completely explicit linear system of equations. This notion satisfies a surprisingly large number of desirable properties -- connections to game theory (especially the von Neumann Minimax Theorem) and potential theory will be sketched; simultaneously, there is a certain "magic" element to all of this that is poorly understood and many open problems remain. I will also sketch some curious related open problems. No prior knowledge of differential geometry (or graphs) is required.