Constructing certain families of 3‐polytopal graphs

Abstract

AbstractLet and be a 3‐polytopal graph such that for every , has at least one vertex of degree . We find the minimal vertex count for . We then describe an algorithm to construct the graphs . A dual statement may be formulated for faces of 3‐polytopes. The ideas behind the algorithm generalise readily to solve related problems. Moreover, given a 3‐polytope comprising a vertex of degree for all , fixed, we define an algorithm to output for a 3‐polytope comprising a vertex of degree , for all , and such that the initial is a subgraph of . The vertex count of is asymptotically optimal, in the sense that it matches the aforementioned minimal vertex count up to order of magnitude, as gets large. In fact, we only lose a small quantity on the coefficient of the second highest term, and this quantity may be taken as small as we please, with the tradeoff of first constructing an accordingly large auxiliary graph.