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The reverse Wiener index of a connected graph $G$ is a variation of the well-known Wiener index $W(G)$ defined as the sum of distances between all unordered pairs of vertices of $G$. It is defined as $\Lambda(G)=\frac{1}{2}n(n-1)d-W(G)$,…

Combinatorics · Mathematics 2012-06-18 Rundan Xing , Bo Zhou

Topological indices are parameters associated with graphs that have many applications in different areas such as mathematical chemistry. Among various topological indices, the Wiener index is classical \cite{w}. In this paper, we prove a…

Combinatorics · Mathematics 2023-03-23 P. Gangaeswari , K. Selvakumar , G. Arunkumar

The Wiener index of a connected graph is the sum of the distances between all unordered pairs of vertices. We provide formulae for the minimum Wiener index of simple triangulations and quadrangulations with connectivity at least $c$, and…

Combinatorics · Mathematics 2021-12-23 Éva Czabarka , Trevor Olsen , Stephen Smith , László A. Székely

(DRAFT VERSION) In this article we present a proof of the famous Kirchoff's Matrix-Tree theorem, which relates the number of spanning trees in a connected graph with the cofactors (and eigenvalues) of its combinatorial Laplacian matrix.…

Discrete Mathematics · Computer Science 2012-08-02 Saad Quader

The Wiener index is a graphical invariant that has found extensive application in chemistry. We define a generating function, which we call the Wiener polynomial, whose derivative is a q-analog of the Wiener index. We study some of the…

Combinatorics · Mathematics 2007-05-23 Bruce E. Sagan , Yeong-Nan Yeh , Ping Zhang

The edge-Wiener index of a connected graph $G$ is defined as the Wiener index of the line graph of $G$. In this paper it is shown that the edge-Wiener index of an edge-weighted graph can be computed in terms of the Wiener index, the…

Combinatorics · Mathematics 2020-10-21 Niko Tratnik

The degree-Kirchhoff index of a connected graph is defined as the sum of the reciprocals of the non-zero eigenvalues of the normalized Laplacian matrix, each multiplied by the graph's total degree. Several studies have recently obtained…

Combinatorics · Mathematics 2024-09-10 Md. Abdus Sahir , Sk. Md. Abu Nayeem

Given a simple connected undirected graph G, the Wiener index W(G) of G is defined as half the sum of the distances over all pairs of vertices of G. In practice, G corresponds to what is known as the molecular graph of an organic compound.…

Discrete Mathematics · Computer Science 2010-12-13 R. Balakrishnan , N. Sridharan , K. V. Iyer

Various questions related to distances between vertices of simple, finite graphs are of interest to extremal graph theorists. The Steiner distance of a set of $k$ vertices is a natural generalization of the regular distance. We extend…

Combinatorics · Mathematics 2023-02-07 Hua Wang , Andrew Zhang

We study the inertia of distance matrices of weighted graphs. Our novel congruence-based proof of the inertia of weighted trees extends to a proof for the inertia of weighted unicyclic graphs whose cycle is a triangle. Partial results are…

Combinatorics · Mathematics 2023-04-26 Jeffrey Cheng , Ian Malcolm Johnson McInnis , Matthew Yee

We present an elementary proof of a generalization of Kirchoff's matrix tree theorem to directed, weighted graphs. The proof is based on a specific factorization of the Laplacian matrices associated to the graphs, which only involves the…

Combinatorics · Mathematics 2019-04-30 Patrick De Leenheer

Given an undirected graph, the resistance distance between two nodes is the resistance one would measure between these two nodes in an electrical network if edges were resistors. Summing these distances over all pairs of nodes yields the…

Information Theory · Computer Science 2015-10-01 Nicolas Boumal , Xiuyuan Cheng

The Wiener index of a graph $G$, denoted $W(G)$, is the sum of the distances between all pairs of vertices in $G$. \'E. Czabarka, et al. conjectured that for an $n$-vertex, $n\geq 4$, simple quadrangulation graph $G$,…

Combinatorics · Mathematics 2020-01-06 Ervin Győri , Addisu Paulos , Chuanqi Xiao

Over all graphs (or unicyclic graphs) of a given order, we characterise those graphs that minimise or maximise the number of connected induced subgraphs. For each of these classes, we find that the graphs that minimise the number of…

Combinatorics · Mathematics 2019-09-18 Audace A. V. Dossou-Olory

The distance of a vertex in a graph is the sum of distances from that vertex to all other vertices of the graph. The Wiener index of a graph is the sum of distances between all its unordered pairs of vertices. A graph has been obtained that…

Combinatorics · Mathematics 2024-07-16 Dinesh Pandey

Vassiliev's knot invariants can be computed in different ways but many of them as Kontsevich integral are very difficult. We consider more visual diagram formulas of the type Polyak-Viro and give new diagram formula for the two basic…

Algebraic Topology · Mathematics 2007-05-23 Svetlana D. Tyurina

For a sequence of complex Wiener-Ito multiple integrals, the equivalence between the convergence of the symmetrized contraction norms and that of the non-symmetrized contraction norms is shown directly by means of a new version of complex…

Probability · Mathematics 2017-06-20 Yong Chen , Guo Jiang

Exact eigendecomposition of large matrices is very expensive, and it is practically impossible to compute exact eigenvalues. Instead, one may set a more modest goal of approaching the empirical distribution of the eigenvalues, recovering…

The aim of this paper is to obtain new inequalities for a large family of generalizations of the Wiener Index and to characterize the set of extremal graphs with respect to them. Our main results provide upper and lower bounds for these…

Combinatorics · Mathematics 2022-01-17 Álvaro Martínez-Pérez , osé M. Rodríguez

A graph is maximal $k$-degenerate if each induced subgraph has a vertex of degree at most $k$ and adding any new edge to the graph violates this condition. In this paper, we provide sharp lower and upper bounds on Wiener indices of maximal…

Combinatorics · Mathematics 2019-08-27 Allan Bickle , Zhongyuan Che