The Beraha number $B_{10}$ is a chromatic root

Abstract

This note exhibits graphs whose chromatic polynomials have the Beraha number $B_{10}=(5+\sqrt{5})/2$ as a root. It was previously known that no other non-integer Beraha number is a chromatic root, and so these examples complete the determination of precisely which Beraha numbers can be chromatic roots.

References in corpus (1)

• Linear bound in terms of maxmaxflow for the chromatic roots of series-parallel graphs