Results 21 to 30 of about 419 (64)

Forbidden Subgraphs for Collapsible Graphs and Supereulerian Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2022
In this paper, we completely characterize the connected forbidden subgraphs and pairs of connected forbidden subgraphs that force a 2-edge-connected (2-connected) graph to be collapsible.
Liu Xia, Xiong Liming
doaj   +1 more source

Hamilton cycles in almost distance-hereditary graphs

open access: yesOpen Mathematics, 2016
Let G be a graph on n ≥ 3 vertices. A graph G is almost distance-hereditary if each connected induced subgraph H of G has the property dH(x, y) ≤ dG(x, y) + 1 for any pair of vertices x, y ∈ V(H).
Chen Bing, Ning Bo
doaj   +1 more source

Dissecting a square into congruent polygons [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2020
We study the dissection of a square into congruent convex polygons. Yuan \emph{et al.} [Dissecting the square into five congruent parts, Discrete Math. \textbf{339} (2016) 288-298] asked whether, if the number of tiles is a prime number $\geq 3$, it is ...
Hui Rao, Lei Ren, Yang Wang
doaj   +1 more source

Loose Hamiltonian cycles forced by large $(k-2)$-degree - sharp version [PDF]

open access: yes, 2018
We prove for all $k\geq 4$ and $1\leq ...
Bastos, Josefran de Oliveira   +4 more
core   +3 more sources

Hamiltonian paths on Platonic graphs

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 30, Page 1613-1616, 2004., 2004
We develop a combinatorial method to show that the dodecahedron graph has, up to rotation and reflection, a unique Hamiltonian cycle. Platonic graphs with this property are called topologically uniquely Hamiltonian. The same method is used to demonstrate topologically distinct Hamiltonian cycles on the icosahedron graph and to show that a regular graph
Brian Hopkins
wiley   +1 more source

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

Lower Bound on the Number of Hamiltonian Cycles of Generalized Petersen Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2020
In this paper, we investigate the number of Hamiltonian cycles of a generalized Petersen graph P (N, k) and prove that Ψ(P(N,3))⩾N⋅αN,\Psi ( {P ( {N,3} )} ) \ge N \cdot {\alpha _N}, where Ψ(P(N, 3)) is the number of Hamiltonian cycles of P(N, 3) and αN ...
Lu Weihua, Yang Chao, Ren Han
doaj   +1 more source

Longest cycles in certain bipartite graphs

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 21, Issue 1, Page 103-106, 1998., 1995
Let G be a connected bipartite graph with bipartition (X, Y) such that |X| ≥ |Y|(≥2), n = |X| and m = |Y|. Suppose, for all vertices x ∈ X and y ∈ Y, dist(x, y) = 3 implies d(x) + d(y) ≥ n + 1. Then G contains a cycle of length 2m. In particular, if m = n, then G is hamiltomian.
Pak-Ken Wong
wiley   +1 more source

Hamiltonicities of Double Domination Critical and Stable Claw-Free Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2019
A graph G with the double domination number γ×2(G) = k is said to be k- γ×2-critical if γ×2 (G + uv) < k for any uv ∉ E(G). On the other hand, a graph G with γ×2 (G) = k is said to be k-γ×2+$k - \gamma _{ \times 2}^ + $-stable if γ×2 (G + uv) = k for any
Kaemawichanurat Pawaton
doaj   +1 more source

Uniquely hamiltonian graphs for many sets of degrees [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science
We give constructive proofs for the existence of uniquely hamiltonian graphs for various sets of degrees. We give constructions for all sets with minimum 2 (a trivial case added for completeness), all sets with minimum 3 that contain an even number (for ...
Gunnar Brinkmann, Matthias De Pauw
doaj   +1 more source

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