拉手蜘蛛图的能量

Energy of the Hand-in-Hand Spider Graph

图G的能量定义为其邻接矩阵的所有特征值的绝对值之和.拉手蜘蛛图定义为从K_2的2个端点分别长出若干条悬挂边和长为2的悬挂路所得到的图.用ζ_n表示点数为n的所有拉手蜘蛛图构成的集合,通过拟序的方法,研究了拉手蜘蛛图的能量,并确定了ζ_n中能量最小的图.

Abstract： The energy of a graph G is defined as the sum of absolute values of all eigenvalues of the graph. The hand-in-hand spider graph was obtained from K2 byadding some pendent edges and pendent paths of length 2 at its two end-vertices. The symbol ξn was used to denote the set of hand- in-hand spider graphs of order n. By using the quasi.order of graph, the energy of the hand-in-hand spider graph was studied,and the graphs with the first smallest energies in ξn were determined.