On Variants of PCGs: A Survey of Current Results and Open Problems
摘要
A graph is called a pairwise compatibility graph (PCG) if there exists an edge-weighted tree where each leaf corresponds to a vertex of the graph, and an edge \({u,v}\) exists in the graph if and only if the weight of the path connecting the leaves u and v in the tree falls within a specified interval. PCGs have been extensively studied, and numerous subclasses and generalizations have been introduced, expanding their applicability and theoretical interest. In this survey, we briefly review the existing results on these variants of PCGs and highlight several intriguing open problems, focusing on the main challenges and potential directions for future research.