|
In graph theory, a graph amalgamation is a relationship between two graphs (one graph is an amalgamation of another). Similar relationships include subgraphs and minors. Amalgamations can provide a way to reduce a graph to a simpler graph while keeping certain structure intact. The amalgamation can then be used to study properties of the original graph in an easier to understand context. Applications include embeddings,〔Gross, Tucker 1987〕 computing genus distribution,〔Gross 2011〕 and Hamiltonian decompositions. == Definition == Let and be two graphs with the same number of edges where has more vertices than . Then we say that is an amalgamation of if there is a bijection and a surjection and the following hold: * If , are two vertices in where , and both and are adjacent by edge in , then and are adjacent by edge in . * If is a loop on a vertex , then is a loop on . * If joins , where , but , then is a loop on .〔Hilton 1984〕 Note that while can be a graph or a pseudograph, it will usually be the case that is a pseudograph. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Graph amalgamation」の詳細全文を読む スポンサード リンク
|