Results 91 to 100 of about 412,655 (203)

The Harary Index of All Unicyclic Graphs with Given Diameter

open access: yesDiscrete Dynamics in Nature and Society, 2018
The Harary index of G is the sum of reciprocals of distance between any two vertices in G. In this paper, we obtain the graphs with the maximum and second-maximum Harary indices among n-vertex unicyclic graphs with diameter d.
Bao-Hua Xing   +3 more
doaj   +1 more source

Maximum Laplacian energy of unicyclic graphs

open access: yesDiscrete Applied Mathematics, 2017
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Kinkar Chandra Das   +3 more
openaire   +3 more sources

On the Multiplicative Sum Zagreb Index of Molecular Trees With Given Order and Number of Branching Vertices

open access: yesJournal of Mathematics, Volume 2025, Issue 1, 2025.
The multiplicative sum Zagreb index of a graph G is defined as the product of the sum of the degrees of adjacent vertices of G. A molecular tree is an acyclic connected graph with maximum degree at most 4. A vertex in a molecular tree with degree 3 or 4 is referred to as a branching vertex. In this paper, we consider the class of all molecular trees of
Sadia Noureen   +6 more
wiley   +1 more source

On the eccentric connectivity index of unicyclic graphs

open access: yes, 2018
Summary: In this paper, we obtain the upper and lower bounds on the eccentricity connectivity index of unicyclic graphs with perfect matchings. Also, we give some lower bounds on the eccentric connectivity index of unicyclic graphs with given matching numbers.
Nacaroglu, Yasar, Maden, Ayse Dilek
openaire   +2 more sources

On the nullity and the matching number of unicyclic graphs [PDF]

open access: yes, 2009
Let G be a graph with n vertices and ν(G) be the matching number of G. Let η(G) denote the nullity of G (the multiplicity of the eigenvalue zero of G). It is well known that if G is a tree, then η(G)=n-2ν(G). Tan and Liu [X. Tan, B.
Yan, Weigen   +2 more
core   +1 more source

On the Maximum SC Index of Chemical Unicyclic Graphs

open access: yesJournal of Mathematics, Volume 2025, Issue 1, 2025.
The sum‐connectivity (SC) index of a graph G is defined as SCG=∑μν∈EG1/Θμ+Θν, where Θμ denotes the vertex degree of μ in G. In this paper, the fourth largest value of SC index for the chemical unicyclic graphs of order n ≥ 7 is determined.
Hui-Yan Cheng   +3 more
wiley   +1 more source

Graphs which have pancyclic complements

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 1978
Let p and q denote the number of vertices and edges of a graph G, respectively. Let Δ(G) denote the maximum degree of G, and G¯ the complement of G. A graph G of order p is said to be pancyclic if G contains a cycle of each length n, 3≤n≤p.
H. Joseph Straight
doaj   +1 more source

Optimal resistor networks

open access: yesMathematika, Volume 70, Issue 4, October 2024.
Abstract Given a graph on n$n$ vertices with m$m$ edges, each of unit resistance, how small can the average resistance between pairs of vertices be? There are two very plausible extremal constructions — graphs like a star, and graphs which are close to regular — with the transition between them occurring when the average degree is 3.
J. Robert Johnson, Mark Walters
wiley   +1 more source

Some Results on the Signless Laplacian Spectra of Unicyclic Graphs [PDF]

open access: yes, 2011
We determine the second to fourth largest (resp. the second smallest) signless Laplacian spectral radii and the second to fourth largest signless Laplacian spreads together with the corresponding graphs in the class of unicyclic graphs with n vertices ...
Muhuo Liu
core   +1 more source

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