Results 51 to 60 of about 878 (132)

Old and new generalizations of line graphs

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 29, Page 1509-1521, 2004., 2004
Line graphs have been studied for over seventy years. In 1932, H. Whitney showed that for connected graphs, edge‐isomorphism implies isomorphism except for K3 and K1,3. The line graph transformation is one of the most widely studied of all graph transformations.
Jay Bagga
wiley   +1 more source

The Completion Numbers of Hamiltonicity and Pancyclicity in Random Graphs

open access: yesRandom Structures &Algorithms, Volume 66, Issue 2, March 2025.
ABSTRACT Let μ(G)$$ \mu (G) $$ denote the minimum number of edges whose addition to G$$ G $$ results in a Hamiltonian graph, and let μ^(G)$$ \hat{\mu}(G) $$ denote the minimum number of edges whose addition to G$$ G $$ results in a pancyclic graph. We study the distributions of μ(G),μ^(G)$$ \mu (G),\hat{\mu}(G) $$ in the context of binomial random ...
Yahav Alon, Michael Anastos
wiley   +1 more source

Long cycles in certain graphs of large degree

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 24, Issue 10, Page 691-697, 2000., 2000
Let G be a connected graph of order n and X = {x ∈ V : d(x) ≥ n/2}. Suppose |X| ≥ 3 and G satisfies the modified Fan′s condition. We show that the vertices of the block B of G containing X form a cycle. This generalizes a result of Fan. We also give an efficient algorithm to obtain such a cycle. The complexity of this algorithm is O(n2). In case G is 2‐
Pak-Ken Wong
wiley   +1 more source

Cycles in Random Bipartite Graphs [PDF]

open access: yes, 2013
In this paper we study cycles in random bipartite graph $G(n,n,p)$. We prove that if $p\gg n^{-2/3}$, then $G(n,n,p)$ a.a.s. satisfies the following. Every subgraph $G'\subset G(n,n,p)$ with more than $(1+o(1))n^2p/2$ edges contains a cycle of length $t$
Shang, Yilun
core  

On the Clean Graph of Commutative Artinian Rings

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2025, Issue 1, 2025.
For a commutative Artinian ring R with unity, the clean graph Cl(R) is a graph with vertices in the form of an ordered pair (e, u), where e is an idempotent and u is a unit of ring R, respectively. Two distinct vertices (e, u) and (f, v) are adjacent in Cl(R) if and only if ef = fe = 0 or uv = vu = 1.
R. Singh   +3 more
wiley   +1 more source

Decomposition of the Product of Cycles Based on Degree Partition

open access: yesDiscussiones Mathematicae Graph Theory, 2019
The Cartesian product of n cycles is a 2n-regular, 2n-connected and bi- pancyclic graph. Let G be the Cartesian product of n even cycles and let 2n = n1+ n2+ ・ ・ ・ + nkwith k ≥ 2 and ni≥ 2 for each i. We prove that if k = 2, then G can be decomposed into
Borse Y. M., Shaikh S. R.
doaj   +1 more source

Pancyclism in hamiltonian graphs

open access: yesDiscrete Mathematics, 1991
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Amar, D.   +3 more
openaire   +1 more source

Graphs with at most two moplexes

open access: yesJournal of Graph Theory, Volume 107, Issue 1, Page 38-69, September 2024.
Abstract A moplex is a natural graph structure that arises when lifting Dirac's classical theorem from chordal graphs to general graphs. The notion is known to be closely related to lexicographic searches in graphs as well as to asteroidal triples, and has been applied in several algorithms related to graph classes, such as interval graphs, claw‐free ...
Clément Dallard   +4 more
wiley   +1 more source

Hamiltonian chordal graphs are not cycle extendible [PDF]

open access: yes, 2014
In 1990, Hendry conjectured that every Hamiltonian chordal graph is cycle extendible; that is, the vertices of any non-Hamiltonian cycle are contained in a cycle of length one greater.
Lafond, Manuel, Seamone, Ben
core  

Hamiltonian and Pancyclic Graphs in the Class of Self-Centered Graphs with Radius Two

open access: yesDiscussiones Mathematicae Graph Theory, 2018
The paper deals with Hamiltonian and pancyclic graphs in the class of all self-centered graphs of radius 2. For both of the two considered classes of graphs we have done the following. For a given number n of vertices, we have found an upper bound of the
Hrnčiar Pavel, Monoszová Gabriela
doaj   +1 more source

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