In this paper, we characterize the extremal graph having the maximal Laplacian spectral radius among the connected bipartite graphs with n vertices and k cut vertices, and describe the extremal graph having the minimal least eigenvalue of the adjacency matrices of all the connected graphs with n ver
Orbits on vertices and edges of finite graphs
β Scribed by Dominique Buset
- Publisher
- Elsevier Science
- Year
- 1985
- Tongue
- English
- Weight
- 134 KB
- Volume
- 57
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
β¦ Synopsis
Given two integers v > 0 and e/> 0, we prove that there exists a finite graph (resp. a finite connected graph) whose automorphism group has exactly v orbits on the set of vertices and e orbits on the set of edges if and only if v ~< 2e + 1 (resp. v ~< e + 1).
π SIMILAR VOLUMES
The eccentricity e(u) of a vertex u in a connected graph G is the distance between u and a vertex furthest from u. The minimum eccentricity among the vertices of G is the radius rad G of G, and the maximum The radial number m(u) of u is the minimum eccentricity among the eccentric vertices of u, wh
Erdiis, P., R.J. Faudree and C.C. Rousseau, Extremal problems involving vertices and edges on odd cycles, Discrete Mathematics 101 (1992) 23-31. We investigate the minimum, taken over all graphs G with n vertices and at least [n\*/4] + 1 edges, of the number of vertices and edges of G which are on c
Let E d (n) be the number of edges joining vertices from a set of n vertices on a d-dimensional cube, maximized over all such sets. We show that E d (n) = r-1 i=0 (l i /2 + i)2 l i , where r and l 0 > l 1 > β’ β’ β’ > l r-1 are nonnegative integers defined by n = r-1 i=0 2 l i .
## Abstract An edge which belongs to more than one clique of a given graph is called a multicliqual edge. We find a necessary and sufficient condition for a graph __H__ to be the clique graph of some graph __G__ without multicliqual edges. We also give a characterization of graphs without multicliq