Regions without complex zeros for chromatic polynomials on graphs with bounded degree

Roberto Fernandez, Aldo Procacci

We prove that the chromatic polynomial $P_{\mathbb{G}}(q)$ of a finite graph $\mathbb{G}$ of maximal degree $\D$ is free of zeros for $\card q\ge C^*(\D)$ with $$ C^*(\D) = \min_{0<x…