摘要

A Bethe tree of k levels, B(k)(d), is a rooted tree such that the root vertex has degree d. the vertices from level 2 to k 1 have degree d + 1 and the vertices at level k are leaves. In this paper, we obtain a recurrence relation for the characteristic polynomial and the Laplacian characteristic polynomial of Bethe trees. As an application, we prove that there are no integral Bethe trees except for the star B(2) (n(2)), and we obtain a recurrence relation for the Laplacian-energy-like invariant of Bethe trees.

  • 出版日期2010-5