Vertex evaluation of multiplex graphs using Forman Curvature

Abstract: Identifying vertices that play a central role is a fundamental problem in network analysis. Although traditional centrality measures have been widely used for this purpose, the growing complexity of contemporary networks necessitates more sophisticated indicators. Forman curvature has recently emerged as a promising approach. In this paper, we define Forman curvature for multilayer networks, a class of complex networks characterized by multiple types of connections or layers between nodes, which are increasingly used to model intricate real-world phenomena. We establish the key properties of Forman curvature in the context of multilayer networks and demonstrate its utility for identifying vertices that hold central positions within these networks. Furthermore, we show that Forman curvature can also serve as an effective tool for the structural classification of entire multilayer networks.