A λ harmonic graph G, a λ-Hgraph G for short, means that there exists a constant λ such that the equality λd(vi) = Σ(vi,vj)∈E(G) d(vj) holds for all i = 1, 2,..., |V(G)|, where d(vi) denotes the d...A λ harmonic graph G, a λ-Hgraph G for short, means that there exists a constant λ such that the equality λd(vi) = Σ(vi,vj)∈E(G) d(vj) holds for all i = 1, 2,..., |V(G)|, where d(vi) denotes the degree of vertex vi. Let ni denote the number of vertices with degree i. This paper deals with the 3-Hgraphs and determines their degree series. Moreover, the 3-Hgraphs with bounded ni (1 ≤ i ≤ 7) are studied and some interesting results are obtained.展开更多
A λ harmonic graph G, a λ-Hgraph G for short, means that there exists a constant A such that the equality λd(ui) = ∑(vi,vj)∈E(G) d(vj) holds for all i = 1, 2,…, |V(G)|, where d(vi) denotes the degr...A λ harmonic graph G, a λ-Hgraph G for short, means that there exists a constant A such that the equality λd(ui) = ∑(vi,vj)∈E(G) d(vj) holds for all i = 1, 2,…, |V(G)|, where d(vi) denotes the degree of vertex vi. In this paper, some harmonic properties of the complement and line graph are given, and some algebraic properties for the λ-Hgraphs are obtained.展开更多
基金supported by the National Natural Science Foundation of China (10771080)the Specialized Research Fund for the Doctoral Program of Higher Eduction (20070574006)
文摘A λ harmonic graph G, a λ-Hgraph G for short, means that there exists a constant λ such that the equality λd(vi) = Σ(vi,vj)∈E(G) d(vj) holds for all i = 1, 2,..., |V(G)|, where d(vi) denotes the degree of vertex vi. Let ni denote the number of vertices with degree i. This paper deals with the 3-Hgraphs and determines their degree series. Moreover, the 3-Hgraphs with bounded ni (1 ≤ i ≤ 7) are studied and some interesting results are obtained.
基金supported by the fund of South China Agricultural University (4900-K08225)supported by the National Natural Science Foundation of China(10771080)Specialized Research Fund for the Doctoral Program of Higher Eduction (20070574006)
文摘A λ harmonic graph G, a λ-Hgraph G for short, means that there exists a constant A such that the equality λd(ui) = ∑(vi,vj)∈E(G) d(vj) holds for all i = 1, 2,…, |V(G)|, where d(vi) denotes the degree of vertex vi. In this paper, some harmonic properties of the complement and line graph are given, and some algebraic properties for the λ-Hgraphs are obtained.