Maps and the Jack symmetric function

David Jackson

University of Waterloo

February 20,
4:15pm
refreshments at 3:45pm
2-338

ABSTRACT 

A map is a 2-cell embedding of a graph in a surface. The determination of the counting series for maps is a question that arises in combinatorics, in geometry, and in physics as a partition function. Tutte, for example. studied the enumeration of maps in the sphere as part of his attack on the Four Colour Problem.

In this talk I will discuss an algebraic approach to determining the counting series for maps in orientable surfaces and in all surfaces (including non-orientable surfaces) in terms of Jack symmetric functions. The indeterminate b in the Jack parameter a=1+b is conjectured to mark an invariant of rooted maps.

The counting series for maps with one vertex is central to the determination of the Euler characteristic of the moduli spaces of complex (b=0; Schur functions) and real algebraic curves (b=1; zonal polynomials). The complex case was treated by Harer and Zagier. If time permits I shall refer briefly to the conjectured combinatorial role of b in this context.


Speaker's Contact Info: dmjackso(at-sign)math.mit.edu


Return to seminar home page

Combinatorics Seminar, Mathematics Department, MIT, sara(at-sign)math.mit.edu

Page loaded on February 01, 2002 at 08:29 AM. Copyright © 1998-99, Sara C. Billey. All rights reserved.