scholarly journals Graph energy change due to edge deletion

2008 ◽  
Vol 428 (8-9) ◽  
pp. 2070-2078 ◽  
Author(s):  
Jane Day ◽  
Wasin So
2015 ◽  
Vol 29 ◽  
pp. 59-73
Author(s):  
Wen-Huan Wang ◽  
Wasin So

The energy of a graph is the sum of the absolute values of its eigenvalues. We propose a new problem on graph energy change due to any single edge deletion. Then we survey the literature for existing partial solution of the problem, and mention a conjecture based on numerical evidence. Moreover, we prove in three different ways that the energy of a cycle graph decreases when an arbitrary edge is deleted except for the order of 4.


If there is an adjacency matrix A, the sum total of the singular values of A is known as the graph energy. We can find the change in energy of a graph by removing the edges using the inequality theorem on singular values. In this paper we discuss about the change in semigraph energy due to deletion of edges and its relation with distance energy


2022 ◽  
Vol 10 (1) ◽  
pp. 193-202
Author(s):  
Iswar Mahato ◽  
M. Rajesh Kannan

Abstract The eccentricity matrix ɛ(G) of a graph G is obtained from the distance matrix of G by retaining the largest distances in each row and each column, and leaving zeros in the remaining ones. The eccentricity energy of G is sum of the absolute values of the eigenvalues of ɛ(G). Although the eccentricity matrices of graphs are closely related to the distance matrices of graphs, a number of properties of eccentricity matrices are substantially different from those of the distance matrices. The change in eccentricity energy of a graph due to an edge deletion is one such property. In this article, we give examples of graphs for which the eccentricity energy increase (resp., decrease) but the distance energy decrease (resp., increase) due to an edge deletion. Also, we prove that the eccentricity energy of the complete k-partite graph Kn 1, ... , nk with k ≥ 2 and ni ≥ 2, increases due to an edge deletion.


1988 ◽  
Vol 53 (4) ◽  
pp. 671-685 ◽  
Author(s):  
Oldřich Pytela ◽  
Miroslav Ludwig

A theoretical description of the effect of changed composition of mixed solvents on processes in solutions has been suggested on the basis of the proportionality between the Gibbs energy change of the process and that of the solvent due to the transition from pure components to the mixture. The additional Gibbs energy has been expressed by means of the so-called classical functions by Margules, van Laar-Wohl, and van Laar-Null. The application to 115 various processes (pK, IR, UV-VIS, NMR, log k, and others) has confirmed that the theoretical presumptions are justified, the most suitable being Margules' 4th order model which shows a statistically significant difference from the models of lower orders.


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