Hassler Whitney (1907-1989) was a major figure in 20th century mathematics, known most widely for his contributions to topology and differential geometry.  But he was also a pioneer in graph theory and a founder of matroid theory.  This talk concentrates on his classic 1932 paper, `The coloring of graphs’, in Annals of Mathematics, which was based closely on his Princeton PhD thesis of the same name.  This work developed the theory of the chromatic polynomial of an arbitrary graph and generalised it to a bivariate polynomial later known as the Whitney rank generating function, which is closely related to the Tutte polynomial.  It shows that these polynomials can be determined just from the non-separable subgraphs of a graph, rather than all subgraphs, and contains an early instance of the exponential formula from enumerative combinatorics.

Knowledge of graph theory since Whitney started his PhD is not required.

How to participate in this seminar:

1. Book your nearest ACE facility;

2. Notify the seminar convenor at La Trobe University  (Yuri Nikolayevsky) to notify you will be participating.

No access to an ACE facility? Contact Maaike Wienk to arrange a temporary Visimeet licence for remote access (limited number of licences available – first come first serve)