Results 61 to 70 of about 314 (174)

The largest eigenvalue of unicyclic graphs

open access: yesDiscrete Mathematics, 2007
The author shows that the largest eigenvalue of the adjacency matrix of a unicyclic graph with the maximum vertex degree \(\Delta\) is bounded from above by \(2\sqrt{\Delta-1}\), while the largest eigenvalue of its Laplacian matrix is bounded by \(\Delta+2\sqrt{\Delta-1}\), with equality in the first case holding for all cycles, and in the second case ...
openaire   +2 more sources

Recognizing Trees From Incomplete Decks

open access: yesJournal of Graph Theory, Volume 110, Issue 3, Page 322-336, November 2025.
ABSTRACT Given a graph G, the unlabeled subgraphs G − v are called the cards of G. The deck of G is the multiset { G − v : v ∈ V ( G ) }. Wendy Myrvold showed that a disconnected graph and a connected graph both on n vertices have at most ⌊ n 2 ⌋ + 1 cards in common and found (infinite) families of trees and disconnected forests for which this upper ...
Gabriëlle Zwaneveld
wiley   +1 more source

Third Smallest Wiener Polarity Index of Unicyclic Graphs

open access: yesFrontiers in Physics, 2020
The Wiener polarity index WP(G) of a graph G is the number of unordered pairs of vertices {u,v} where the distance between u and v is 3. In this paper, we determine the third smallest Wiener polarity index of unicyclic graphs. Moreover, the corresponding
Wei Fang   +5 more
doaj   +1 more source

The Moran Process on a Random Graph

open access: yesRandom Structures &Algorithms, Volume 66, Issue 3, May 2025.
ABSTRACT We study the fixation probability for two versions of the Moran process on the random graph Gn,p$$ {G}_{n,p} $$ at the threshold for connectivity. The Moran process models the spread of a mutant population in a network. Throughout the process, there are vertices of two types, mutants, and non‐mutants.
Alan Frieze, Wesley Pegden
wiley   +1 more source

Extremal Unicyclic Graphs With Minimal Distance Spectral Radius

open access: yesDiscussiones Mathematicae Graph Theory, 2014
The distance spectral radius ρ(G) of a graph G is the largest eigenvalue of the distance matrix D(G). Let U (n,m) be the class of unicyclic graphs of order n with given matching number m (m ≠ 3).
Lu Hongyan, Luo Jing, Zhu Zhongxun
doaj   +1 more source

Computing the vertex separation of unicyclic graphs

open access: yesInformation and Computation, 2004
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
John A. Ellis, Minko Markov
openaire   +1 more source

Selection of an Optimal Warehouses Using Global Regular Domination in Graphs

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2025, Issue 1, 2025.
Let G = (V, E) be a simple graph. A subset S of V (G) is said to be global dominating set if S is a dominating set of the given graph G and its complement G. A subset whose induced subgraph is regular in G is also regular in G. A dominating set D of V (G) is called a regular dominating set if hSi is regular. In this article, we introduce global regular
R. Sundareswaran   +6 more
wiley   +1 more source

On Minimum Generalized Degree Distance Index of Cyclic Graphs

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 2023
Topological index (TI) is a mapping that associates a real number to the under study (molecular) graph which predicts its various physical and chemical properties.
Nadia Khan   +3 more
doaj   +1 more source

Stress in Directed Graphs: A Generalization of Graph Stress

open access: yesJournal of Applied Mathematics, Volume 2025, Issue 1, 2025.
In graph theory, centrality measures are used to identify the most important or influential nodes within a network. Stress centrality is one such measure, which helps quantify how “stressed” a node is within the overall graph structure based on the number of shortest paths that pass through it. Stress centrality provides a more thorough assessment of a
K. V. Madhumitha   +4 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

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