Abstract:
A trivial lower bound for the $2$-distance chromatic number $\chi_2(G)$ of any graph $G$ with maximum degree $\Delta$ is $\Delta+1$. It is known that if $G$ is planar and its girth is at least $7$, then for large enough $\Delta$ this bound is sharp, while for girth $6$ it is not true. We prove that if $G$ is planar, its girth is $6$, every edge is incident with a $2$-vertex, and $\Delta\ge31$, then $\chi_2(G)=\Delta+1$.