A signed bipartite graph G(U,V) is a bipartite graph in which each edge is assigned a positive or a negative sign. The signed degree of a vertex x in G(U, V) is the number of positive edges incident ...

Coxeter theory investigates groups generated by reflections and the geometric structures arising from their actions, such as root systems and Dynkin diagrams. This body of work underpins vast areas of ...

A drawing of a graph G in the plane has the vertices represented by distinct points and the edges represented by polygonal lines joining their endpoints such that: no edge contains a vertex other than ...

Taiwanese Journal of Mathematics, Vol. 13, No. 5 (October 2009), pp. 1397-1410 (14 pages) Let G be a simple undirected graph. Denote by mi(G) (respectively, xi(G)) the number of maximal (respectively, ...