Laplacian Coefficient of some Rooted Trees

Document Type: Original Scientific Paper


1 Department of Mathematics, Islamic Azad University, Science and Researcher Branch Tehran, I. R. Iran

2 Department of Pure Mathematics, Faculty of Mathematical Sciences, University of Kashan, Kashan, I. R. Iran



Abstract. The Laplacian characteristic polynomial of an n-vertex graph G has the form f(G,x) = x^n+∑l_ix^n-i. In this paper, the fourth and fifth coefficient of f(G,x), will be investigated, where G is a T(k,t) tree in which a rooted tree with degree sequence k,k,···,k,1,1,···,1 is denoted by T(k,t).