Friday, February 6, 2009
3:30 pm, MC 5158

Tutte Seminar Series
Combinatorics & Optimization
Winter 2009


Bruce Richmond
University of Waterloo

The Asymptotic Enumeration of Maps

One area founded by W. T. Tutte in the 1960s is the enumeration of planar maps, graphs drawn in the plane with n edges. There has been a great deal of subsequent work and the area is still developing, especially when the graphs are embedded on a surface of genus g. Recently with Ed Bender and Jason Gao the asymptotic expression for the number of these maps on an orientable surface of genus g has been greatly simplified. More recently, with Nick Wormald, connections with the Painleve transcendent of type I and Gevrey Type 1 divergent series have been found. This work will be surveyed from a historical point of view. The results and methods are sometimes complicated so only the ideas and simpler results will be mentioned.