Abstract of Colloquium talk at Math Department of WVU, February 20, 1997

Professor Edgar G. Whitehead, Jr.

University of Pittsburgh

Chromatic Equivalence and Chromatic Uniqueness

The chromatic polynomial was used by G. D. Birkhoff in an attempt to solve the four color problem. Two graphs are said to be chromatically equivalent if their chromatic polynomials are equal. A graph G is said to be chromatically unique if any graph chromatically equivalent to G, is isomorphic to G. There is a vast literature (more than 450 papers) on chromatic polynomials. In this talk, we will discuss several chromatic equivalence and chromatic uniqueness results.