[PAST EVENT] Mathematics Colloquium - Tyrone Crisp, University of Maine

April 12, 2024
2pm - 3pm
Jones Hall, Room 302
200 Ukrop Way
Williamsburg, VA 23185Map this location
Access & Features
  • Free food
  • Open to the public
Jones Hall

Coloring, Counting, and Characters

Many different kinds of problems—from solving sudoku, to making maps easier to read—can be formulated as problems about colorings of graphs. In 1912 Birkhoff introduced a polynomial function that counts graph colorings, and 60 years later Stanley pointed out the intriguing fact that Birkhoff’s polynomial also counts the acyclic orientations of the graph. Later still, Hanlon showed how to adapt Birkhoff’s and Stanley’s results to the problem of counting colorings and orientations modulo symmetry. In this talk I will give a student-friendly, expository account of this work of Birkhoff, Stanley, and Hanlon. I will also briefly present some joint work with Caleb Hill and Aidan McEnaney, in which we show that Hanlon's results have a natural interpretation and extension in the language of group representations and Hopf algebras.

Sponsored by: Mathematics


Pierre Clare