English
Related papers

Related papers: 4-regular 4-connected Hamiltonian graphs with few …

200 papers

In this paper we extend counting of traversing Hamiltonian cycles from 2-tiled graphs to generalized tiled graphs. We further show that, for a fixed finite set of tiles, counting traversing Hamiltonian cycles can be done in linear time with…

Combinatorics · Mathematics 2023-04-28 Alen Vegi Kalamar

A graph $G$ is called a $2K_2$-free graph if it does not contain $2K_2$ as an induced subgraph. In 2014, Broersma, Patel and Pyatkin showed that every 25-tough $2K_2$-free graph on at least three vertices is Hamiltonian. Recently, Shan…

Combinatorics · Mathematics 2021-12-06 Katsuhiro Ota , Masahiro Sanka

A set of vertices in a graph is a Hamiltonian subset if it induces a subgraph containing a Hamiltonian cycle. Kim, Liu, Sharifzadeh and Staden proved that among all graphs with minimum degree $d$, $K_{d+1}$ minimises the number of…

Combinatorics · Mathematics 2023-01-19 Stijn Cambie , Jun Gao , Hong Liu

It has long been known that there exist finite connected tetravalent arc-transitive graphs with arbitrarily large vertex-stabilisers. However, beside a well known family of exceptional graphs, related to the lexicographic product of a cycle…

Combinatorics · Mathematics 2010-10-14 Primoz Potocnik , Pablo Spiga , Gabriel Verret

We prove that, in the Gilbert model for a random geometric graph, almost every graph becomes Hamiltonian exactly when it first becomes 2-connected. This answers a question of Penrose. We also show that in the k-nearest neighbor model, there…

Probability · Mathematics 2012-11-09 József Balogh , Béla Bollobás , Michael Krivelevich , Tobias Müller , Mark Walters

We characterise the quartic (i.e. 4-regular) multigraphs with the property that every edge lies in a triangle. The main result is that such graphs are either squares of cycles, line multigraphs of cubic multigraphs, or are obtained from…

Combinatorics · Mathematics 2013-08-02 Florian Pfender , Gordon F. Royle

The first part (page 1 - 7) of this article presents the currently known examples of 4-regular matchstick graphs with 63 - 70 vertices. The second part (page 8 - 15) presents the currently known examples of $(2;4)$-regular matchstick graphs…

Combinatorics · Mathematics 2021-10-14 Mike Winkler

Lin-Lu-Yau introduced an interesting notion of Ricci curvature for graphs and obtained a complete characterization for all Ricci-flat graphs with girth at least five [1]. In this paper, we propose a concrete approach to construct an…

Combinatorics · Mathematics 2018-07-20 Weihua He , Jun Luo , Chao Yang , Wei Yuan

Let $H$ be a fixed graph and $\mathcal{G}$ a subcritical graph class. In this paper we show that the number of occurrences of $H$ (as a subgraph) in a uniformly at random graph of size $n$ in $\mathcal{G}$ follows a normal limiting…

Combinatorics · Mathematics 2018-08-06 Michael Drmota , Lander Ramos , Juanjo Rué

For large $n$ we determine the maximum number of induced 6-cycles which can be contained in a planar graph on $n$ vertices, and we classify the graphs which achieve this maximum. In particular we show that the maximum is achieved by the…

Combinatorics · Mathematics 2024-01-23 Michael Savery

For all integers $k$ with $k\geq 2$, if $G$ is a balanced $k$-partite graph on $n\geq 3$ vertices with minimum degree at least \[…

Combinatorics · Mathematics 2020-05-28 Louis DeBiasio , Nicholas Spanier

A conjecture of Jackson from 1981 states that every $d$-regular oriented graph on $n$ vertices with $n\leq 4d+1$ is Hamiltonian. We prove this conjecture for sufficiently large $n$. In fact we prove a more general result that for all…

Combinatorics · Mathematics 2025-04-30 Allan Lo , Viresh Patel , Mehmet Akif Yıldız

Motivated by the theory of crystallizations, we consider an equivalence relation on the class of $3$-regular colored graphs and prove that up to this equivalence (a) there exists a unique contracted 3-regular colored graph if the number of…

Combinatorics · Mathematics 2017-08-01 Biplab Basak

Hakimi and Schmeichel determined a sharp lower bound for the number of cycles of length 4 in a maximal planar graph with $n$ vertices, $n\geq 5$. It has been shown that the bound is sharp for $n = 5,12$ and $n\geq 14$ vertices. However, the…

Combinatorics · Mathematics 2023-06-08 Ervin Győri , Addisu Paulos , Oscar Zamora

A famous conjecture of Lov\'asz states that every connected vertex-transitive graph contains a Hamilton path. In this article we confirm the conjecture in the case that the graph is dense and sufficiently large. In fact, we show that such…

Combinatorics · Mathematics 2017-07-31 Demetres Christofides , Jan Hladký , András Máthé

We show that 4-connected plane triangulations can be redrawn such that edges are represented by straight segments and the vertices are covered by a set of at most $\sqrt{2n}$ lines each of them horizontal or vertical. The same holds for all…

Combinatorics · Mathematics 2019-08-15 Stefan Felsner

In 1990, Hendry conjectured that all Hamiltonian chordal graphs are cycle extendable. After a series of papers confirming the conjecture for a number of graph classes, the conjecture is yet refuted by Lafond and Seamone in 2015. Given that…

Discrete Mathematics · Computer Science 2021-07-06 Guozhen Rong , Wenjun Li , Jianxin Wang , Yongjie Yang

Supergrid graphs contain grid graphs and triangular grid graphs as their subgraphs. The Hamiltonian cycle and path problems for general supergrid graphs were known to be NP-complete. A graph is called Hamiltonian if it contains a…

Discrete Mathematics · Computer Science 2019-05-07 Fatemeh Keshavarz-Kohjerdi , Ruo-Wei Hung

In this paper we consider the question of the existence of Hamiltonian circuits in the tope graphs of central arrangements of hyperplanes. Some of the results describe connections between the existence of Hamiltonian circuits in the…

Combinatorics · Mathematics 2016-10-18 Yvonne Kemper , Jim Lawrence

All finite simple self $2$-distance graphs with no $4$-cycle, diamond, or triangles with a common vertex are determined. Utilizing these results, it is shown that there is no cubic self $2$-distance graphs.

Combinatorics · Mathematics 2019-08-15 Ali Azimi , Mohammad Farrokhi Derakhshandeh Ghouchan