n阶连通图G的路由选择R是由连接G的每个有向顶点对的n(n-1)条路组成.R经过G的每个顶点(每条边)的路的最大条数称为G关于R的点转发指数ξ(G,R)(边转发指数π(G,R)).对G的所有路由选择R,ξ(G,R)(π(G,R))的最小值称为G的点转发指数ξ(G)(边转发指数π(G)).对于k正则k连通图G,Fernandez de la Vega和Manoussakis[Discrete Applied Mathematics,1989,23(2):103—123]证明ξ(G)≤(n—1)·[(n-k-1)/k]和π(G)≤n[(n-k-1)/k],并且猜想ξ(G)≤[(n-k)(n-k-1)/k].我们分别改进了ξ(G)≤(n—1)[(n-k-1)/k]-(n-k-1)和π(G)≤n[(n-k-1)/k]-(n-k),并且证明了猜想对k=3的情形.
A routing R of a connected graph G of order n is a collection of n (n--l) paths connecting every ordered pair of vertices of G. The vertex forwarding index ξ(G,R) (resp. the edge-forwarding index π(G,R)) of G with respect to R is defined to be the maximum number of paths of R passing through any vertex (resp. any edge) of G. The vertex-forwarding index ξ(G) (resp. the edge-forwarding index π(G)) of G is defined to be the minimum ξ(G,R) (resp. π(G,R)) over all routings R of G. For a h-regular k-connected graph G, it was shown by Fernandez de la Vega and Manoussakis [Discrete Applied Mathematics, 1989, 23(2): 103-123]that ξ(G)≤(n-1)[(n-k-1)/k ] and π(G)≤n [(n-k-1)/k ], and conjectured that ξ(G)≤[(n-k) (n-k-1)/k]. The upper bounds as ξ(G)≤(n-1)[(n-k-1)/k]-(n-k-1) and π(G)≤n[(n-k-1)/k]-(n-k) were improved, and the conjecture for k=3 was proved.