Wiener index of iterated line graphs of trees homeomorphic to

نویسندگان

  • Martin Knor
  • Primoz Potocnik
  • Riste Skrekovski
چکیده

Let G be a graph. Denote by L(G) its i-iterated line graph and denote by W (G) its Wiener index. Dobrynin, Entringer and Gutman stated the following problem: Does there exist a non-trivial tree T and i ≥ 3 such that W (L(T )) = W (T )? In a series of five papers we solve this problem. In a previous paper we proved that W (L(T )) > W (T ) for every tree T that is not homeomorphic to a path, claw K1,3 and to the graph of “letter H”, where i ≥ 3. Here we prove that W (L(T )) > W (T ) for every tree T homeomorphic to the claw, T 6= K1,3 and i ≥ 4.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

On a conjecture about Wiener index in iterated line graphs of trees

Let G be a graph. Denote by L(G) its i-iterated line graph and denote by W (G) its Wiener index. There is a conjecture which claims that there exists no nontrivial tree T and i ≥ 3, such that W (L(T )) = W (T ), see [5]. We prove this conjecture for trees which are not homeomorphic to the claw K1,3 and the graph of letter H.

متن کامل

Complete solution of equation W(L3(T))=W(T) for the Wiener index of iterated line graphs of trees

Let G be a graph. The Wiener index of G, W (G), is defined as the sum of distances between all pairs of vertices of G. Denote by L i (G) its i-iterated line graph. In the talk, we will consider the equation W (L i (T)) = W (T) where T is a tree and i ≥ 1.

متن کامل

MORE ON EDGE HYPER WIENER INDEX OF GRAPHS

‎Let G=(V(G),E(G)) be a simple connected graph with vertex set V(G) and edge‎ ‎set E(G)‎. ‎The (first) edge-hyper Wiener index of the graph G is defined as‎: ‎$$WW_{e}(G)=sum_{{f,g}subseteq E(G)}(d_{e}(f,g|G)+d_{e}^{2}(f,g|G))=frac{1}{2}sum_{fin E(G)}(d_{e}(f|G)+d^{2}_{e}(f|G)),$$‎ ‎where de(f,g|G) denotes the distance between the edges f=xy and g=uv in E(G) and de(f|G)=∑g€(G)de(f,g|G). ‎In thi...

متن کامل

On the edge reverse Wiener indices of TUC4C8(S) nanotubes

The edge versions of reverse Wiener indices were introduced by Mahmiani et al. very recently. In this paper, we find their relation with ordinary (vertex) Wiener index in some graphs. Also, we compute them for trees and TUC4C8(s) naotubes.

متن کامل

Peripheral Wiener Index of a Graph

The eccentricity of a vertex $v$ is the maximum distance between $v$ and anyother vertex. A vertex with maximum eccentricity is called a peripheral vertex.The peripheral Wiener index $ PW(G)$ of a graph $G$ is defined as the sum ofthe distances between all pairs of peripheral vertices of $G.$ In this paper, weinitiate the study of the peripheral Wiener index and we investigate its basicproperti...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Discrete Mathematics

دوره 313  شماره 

صفحات  -

تاریخ انتشار 2013