A k-partition Π = {S1,S2, . . . ,Sk} of V (G) is resolving if for every two distinct vertices u and v of a connected graph G, there is a set Si in Π so that the minimum distance between u and a vertex of Si is different from the minimum distance between v and a vertex of Si. A resolving partition Π is said to be connected if each subgraph < Si > induced by Si (1 ≤ i ≤ k) is connected in G. In t...

Let G be a simple connected graph with pendant vertex set ∂V and nonpendant vertex set V0. The signless Laplacian matrix of G is denoted by Q(G). The signless Dirichlet eigenvalue is a real number λ such that there exists a function f ̸= 0 on V (G) such that Q(G)f(u) = λf(u) for u ∈ V0 and f(u) = 0 for u ∈ ∂V . The signless Dirichlet spectral radius λ(G) is the largest signless Dirichlet eigenva...

Let α (G) denote the maximum size of an independent set of vertices and μ (G) be the cardinality of a maximum matching in a graph G. A matching saturating all the vertices is a perfect matching. If α (G) + μ (G) = |V (G)|, then G is called a König-Egerváry graph. A graph is unicyclic if it has a unique cycle. It is known that a maximum matching can be found in O(m •√n) time for a graph with n v...

Several matrices can be associated to a graph such as the adjacency matrix or the Laplacian matrix. The spectrum of these matrices gives some informations about the structure of the graph and the question “Which graphs are determined by their spectrum?” remains a difficult problem in algebraic graph theory. In this article we enlarge the known families of graphs determined by their spectrum by ...

Let U(n, k) be the set of non-bipartite unicyclic graphs with n vertices and k pendant vertices, where n ≥ 4. In this paper, the unique graph with the minimal least eigenvalue of the signless Laplacian among all graphs in U(n, k) is determined. Furthermore, it is proved that the minimal least eigenvalue of the signless Laplacian is an increasing function in k. Let Un denote the set of non-bipar...

Copyright q 2012 X. Pai and S. Liu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Let Φ G, λ det λIn − L G ∑n k 0 −1 ck G λn−k be the characteristic polynomial of the Laplacian matrix of a graph G of order n. In this paper, we g...

Let [Formula: see text] be a connected graph on the vertex set text]. Then In this paper, we prove that if is unicyclic graph, then depth of bounded below by Also, characterize with and We compute one distinguished extremal Betti numbers If obtained attaching whiskers at some vertices cycle length text], show Furthermore, each these cases, classify uniqueness number graphs.

A team of r revolutionaries and a team of s spies play a game on a graph G. Initially, revolutionaries and then spies take positions at vertices. In each subsequent round, each revolutionary may move to an adjacent vertex or not move, and then each spy has the same option. The revolutionaries want to hold an unguarded meeting, meaning m revolutionaries at some vertex having no spy at the end of...

We introduce the concept of minimum edge cover for an induced subgraph in a graph. Let [Formula: see text] be unicyclic graph with unique odd cycle and its ideal. compute exact values all symbolic defects using describe one method to find quasi-polynomial associated ideal text]. classify class graphs when some power maximal annihilates any fixed Also those graphs, we Hilbert function module

Abstract The graph-parameters mainly studies vertex degree and distance between unordered vertices. There are many graph-parameters, this paper focuses on the Gutman index. For sake of discussion, puts forward concept “ contribution” based relationship index graph vertex-Gutman On basis, we discussed unicyclic with pendent edges in odd even parts, gave corresponding extremal graphs, which lays ...