Scaffold for the polyhedral embedding of cubic graphs

Abstract

Let $G$ be a cubic graph and $\Pi$ be a polyhedral embedding of this graph. The extended graph, $G^{e},$ of $\Pi$ is the graph whose set of vertices is $V(G^{e})=V(G)$ and whose set of edges $E(G^{e})$ is equal to $E(G) \cup \mathcal{S}$, where $\mathcal{S}$ is constructed as follows: given two vertices $t_0$ and $t_3$ in $V(G^{e})$ we say $[t_0 t_3] \in \mathcal{S},$ if there is a $3$--path, $(t_0 t_1 t_2 t_3) \in G$ that is a $\Pi$-- facial subwalk of the embedding. We prove that there is a one to one correspondence between the set of possible extended graphs of $G$ and polyhedral embeddings of $G$.