Results 21 to 30 of about 891,390 (207)

Unicyclic Graphs with the Fourth Extremal Wiener Indices

open access: yesJournal of Chemistry, 2020
A graph is called unicyclic if the graph contains exactly one cycle. Unicyclic graphs with the fourth extremal Wiener indices are characterized. It is shown that, among all unicyclic graphs with n≥8 vertices, C5Sn−4 and C2u1,u2S3,Sn−4 attain the fourth ...
Guangfu Wang   +3 more
doaj   +1 more source

On the Maximum Sombor Index of Unicyclic Graphs with a Fixed Girth

open access: yesJournal of Mathematics, 2022
Let G be a graph having the set of edges EG. Represent by dGu the degree of a vertex u of G. The Sombor (SO) index of G is defined as SOG=∑uv∈EGdGu2+dGv2. The length of a shortest cycle in a graph G is known as the girth of G.
B. Senthilkumar   +5 more
doaj   +1 more source

On symmetric division deg index of unicyclic graphs and bicyclic graphs with given matching number

open access: yesAIMS Mathematics, 2021
Nowadays, it is an important task to find extremal values on any molecular descriptor with respect to different graph parameters. In a molecular graph, the vertices represent the atoms and the edges represent the chemical bonds in the terms of graph ...
Xiaoling Sun, Yubin Gao, Jianwei Du
doaj   +1 more source

Properties of characteristic polynomial and eigenvalues of antiadjacency matrix of directed unicyclic helm graph

open access: yes, 2021
A directed unicyclic graph is a directed graph that has only one directed cycle subgraph. A directed unicyclic helm graph Hn→ is obtained from a directed wheel graph Wn→ by adjoining a directed pendant edge at each vertex of the cycle.
Rizky P. Okfradifa, S. Aminah, K. Sugeng
semanticscholar   +1 more source

Gallai-Edmonds decomposition of unicyclic graphs from null space [PDF]

open access: yesThe American Journal of Combinatorics, 2022
In this paper, we compute the Gallai-Edmonds decomposition of a unicyclic graph $G$ using linear algebraic tools. More precisely, the Gallai-Edmonds decomposition of $G$ is obtained from the null space associated with adjacency matrices of its subtrees.
Luiz Emilio Allem   +3 more
doaj   +2 more sources

Generating graceful unicyclic graphs from a given forest

open access: yesAKCE International Journal of Graphs and Combinatorics, 2020
Acharya (1982) proved that every connected graph can be embedded in a graceful graph. The generalization of this result that, any set of graphs can be packed into a graceful graph was proved by Sethuraman and Elumalai (2005). Recently, Sethuraman et al. (
G. Sethuraman, V. Murugan
doaj   +1 more source

New Diagonal Graph Ramsey Numbers of Unicyclic Graphs

open access: yesTheory and Applications of Graphs, 2023
Grossman conjectured that R(G, G) = 2 · |V (G)| − 1, for all simple connected unicyclic graphs G of odd girth and |V (G)| ≥ 4. In this note, we prove his conjecture for various classes of G containing a triangle.
Richard M. Low, Ardak Kapbasov
doaj   +1 more source

Binomial edge ideals of unicyclic graphs [PDF]

open access: yesInternational Journal of Algebra and Computation, 2021
Let [Formula: see text] be a connected graph on the vertex set [Formula: see text]. Then [Formula: see text]. In this paper, we prove that if [Formula: see text] is a unicyclic graph, then the depth of [Formula: see text] is bounded below by [Formula: see text]. Also, we characterize [Formula: see text] with [Formula: see text] and [Formula: see text].
openaire   +2 more sources

Regular Turán numbers and some Gan–Loh–Sudakov‐type problems

open access: yesJournal of Graph Theory, Volume 102, Issue 1, Page 67-85, January 2023., 2023
Abstract Motivated by a Gan–Loh–Sudakov‐type problem, we introduce the regular Turán numbers, a natural variation on the classical Turán numbers where we restrict ourselves to the class of regular graphs. Among other results, we prove a striking supersaturation version of Mantel's theorem in the case of a regular host graph of odd order.
Stijn Cambie   +2 more
wiley   +1 more source

Ordering non-bipartite unicyclic graphs with pendant vertices by the least Q-eigenvalue

open access: yesJournal of Inequalities and Applications, 2016
A unicyclic graph is a connected graph whose number of edges is equal to the number of vertices. Fan et al. (Discrete Math. 313:903-909, 2013) and Liu et al. (Electron. J.
Shu-Guang Guo   +3 more
doaj   +1 more source

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