The first two cacti with larger multiplicative eccentricity resistance-distance


Yunchao Hong, Zhongxun Zhu




For a connected graph G, the multiplicative eccentricity resistance-distance ξ∗R(G) is defined as ξ∗R(G) = ∑ {x,y}⊆V(G) ε(x) · ε(y)RG(x, y), where ε(·) is the eccentricity of the corresponding vertex and RG(x, y) is the effective resistance between vertices x and y. A cactus is a connected graph in which any two simple cycles have at most one vertex in common. Let Cat(n; t) be the set of cacti possessing n vertices and t cycles, where 0 ≤ t ≤ n−12 . In this paper, we first introduce some edge-grafting transformations which will increase ξ∗R(G). As their applications, the extremal graphs with maximum and second-maximum ξ ∗ R(G)-value in Cat(n; t) are characterized, respectively