Thomas Perrett

Technical University of Denmark

Roots of the chromatic polynomial, spanning trees and minors

The real and complex roots of chromatic polynomials, which we call chromatic roots, have been studied since the 1940s yet it is not well understood how structural properties of graphs affect their chromatic roots. In this talk we survey some results and open problems, and present recent work on the following question: For a minor-closed class of graphs, what is the infimum of the non-trivial real chromatic roots of the graphs in that class?