Tournaments with the same neighbourhoods
Tournois et ordres médians pour une opinion
Dans cet article on étudie les propriétés d’ordres totaux à distance minimum d’un ensemble de tournois ; on montre, par exemple, que ces ordres contiennent l’ordre d’unanimité. On étudie la fonction maximum de la distance entre un ordre total et tournois définis sur un ensemble à éléments ; on donne sa valeur exacte pour pair, un encadrement pour impair, et sa valeur limite pour tendant vers l’infini.
Transitive closure and transitive reduction in bidirected graphs
In a bidirected graph, an edge has a direction at each end, so bidirected graphs generalize directed graphs. We generalize the definitions of transitive closure and transitive reduction from directed graphs to bidirected graphs by introducing new notions of bipath and bicircuit that generalize directed paths and cycles. We show how transitive reduction is related to transitive closure and to the matroids of the signed graph corresponding to the bidirected graph.
Transversals of circuits in the lexicographic product of directed graphs
Tripartite multidigraphs and imbalances
Tutte polynomial, subgraphs, orientations and sandpile model: new connections via embeddings.