English
Related papers

Related papers: Turns in Hamilton cycles of rectangular grids

200 papers

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

In this paper we give an approximate answer to a question of Nash-Williams from 1970: we show that for every \alpha > 0, every sufficiently large graph on n vertices with minimum degree at least (1/2 + \alpha)n contains at least n/8…

Combinatorics · Mathematics 2015-03-13 Demetres Christofides , Daniela Kühn , Deryk Osthus

A Hamilton cycle in a directed graph $G$ is a cycle that passes through every vertex of $G$. A Hamiltonian decomposition of $G$ is a partition of its edge set into disjoint Hamilton cycles. In the late $60$s Kelly conjectured that every…

Combinatorics · Mathematics 2016-10-03 Asaf Ferber , Eoin Long , Benny Sudakov

We investigate the minimum number of cycles of specified lengths in planar $n$-vertex triangulations $G$. It is proven that this number is $\Omega(n)$ for any cycle length at most $3 + \max \{ {\rm rad}(G^*), \lceil…

Combinatorics · Mathematics 2025-06-13 On-Hei Solomon Lo , Carol T. Zamfirescu

A Hamiltonian cycle of a graph is a closed path that visits each site once and only once. I study a field theoretic representation for the number of Hamiltonian cycles for arbitrary graphs. By integrating out quadratic fluctuations around…

Statistical Mechanics · Physics 2009-10-30 Saburo Higuchi

In this series of papers, the primary goal is to enumerate Hamiltonian cycles (HC's) on the grid cylinder graphs $P_{m+1}\times C_n$, where $n$ is allowed to grow whilst $m$ is fixed. In Part~I, we studied the so-called non-contractible…

Combinatorics · Mathematics 2022-10-21 Olga Bodroža-Pantić , Harris Kwong , Jelena Djokić , Rade Doroslovački , Milan Pantić

In order to find Hamiltonian cycle, algorithm should find edges that creates a Hamiltonian cycle. Higher number of edges creates more possibilities to check to solve the problem. Algorithm rests on analysis of original graph and opposite…

Data Structures and Algorithms · Computer Science 2022-08-25 Paweł Kaftan

We investigate the appearance of the square of a Hamilton cycle in the model of randomly perturbed graphs, which is, for a given $\alpha \in (0,1)$, the union of any $n$-vertex graph with minimum degree $\alpha n$ and the binomial random…

Combinatorics · Mathematics 2025-07-18 Julia Böttcher , Olaf Parczyk , Amedeo Sgueglia , Jozef Skokan

A covering of a digraph $D$ by Hamilton cycles is a collection of directed Hamilton cycles (not necessarily edge-disjoint) that together cover all the edges of $D$. We prove that for $1/2 \geq p\geq \frac{\log^{20} n}{n}$, the random…

Combinatorics · Mathematics 2024-10-18 Asaf Ferber , Marcelo Sales , Mason Shurman

We prove that the minimum number of Hamilton cycles in a hamiltonian threshold graph of order $n$ is $2^{\lfloor (n-3)/2\rfloor}$ and this minimum number is attained uniquely by the graph with degree sequence $n-1,n-1,n-2,\ldots,\lceil…

Combinatorics · Mathematics 2018-02-27 Pu Qiao , Xingzhi Zhan

We conjecture that every oriented graph $G$ on $n$ vertices with $\delta ^+ (G) , \delta ^- (G) \geq 5n/12$ contains the square of a Hamilton cycle. We also give a conjectural bound on the minimum semidegree which ensures a perfect packing…

Combinatorics · Mathematics 2010-11-22 Andrew Treglown

In this paper we prove a sufficient condition for the existence of a Hamilton cycle, which is applicable to a wide variety of graphs, including relatively sparse graphs. In contrast to previous criteria, ours is based on only two…

Combinatorics · Mathematics 2007-05-23 Dan Hefetz , Michael Krivelevich , Tibor Szabo

We propose the following conjecture extending Dirac's theorem: if $G$ is a graph with $n\ge 3$ vertices and minimum degree $\delta(G)\ge n/2$, then in every orientation of $G$ there is a Hamilton cycle with at least $\delta(G)$ edges…

Combinatorics · Mathematics 2023-03-13 Lior Gishboliner , Michael Krivelevich , Peleg Michaeli

We survey some recent results on long-standing conjectures regarding Hamilton cycles in directed graphs, oriented graphs and tournaments. We also combine some of these to prove the following approximate result towards Kelly's conjecture on…

Combinatorics · Mathematics 2010-06-04 Daniela Kühn , Deryk Osthus

Let $\mathbf{G}=\{G_1, \ldots, G_m\}$ be a graph collection on a common vertex set $V$ of size $n$ such that $\delta(G_i) \geq (1+o(1))n/2$ for every $i \in [m]$. We show that $\mathbf{G}$ contains every Hamilton cycle pattern. That is, for…

Combinatorics · Mathematics 2023-10-09 Candida Bowtell , Patrick Morris , Yanitsa Pehova , Katherine Staden

\noindent An \textit{\(m \times n\) grid graph} is the induced subgraph of the square lattice whose vertex set consists of all integer grid points \(\{(i,j) : 0 \leq i < m,\ 0 \leq j < n\}\). Let $H$ and $K$ be Hamiltonian cycles in an $m…

Combinatorics · Mathematics 2026-01-13 Albi Kazazi

It is shown that for any choice of four different vertices x_1,...,x_4 in a 2-block G of order p>3, there is a hamiltonian cycle in G^2 containing four different edges x_iy_i of E(G) for certain vertices y_i, i=1,2,3,4. This result is best…

Combinatorics · Mathematics 2019-06-06 Jan Ekstein , Herbert Fleischner

We propose an improved algorithm for counting the number of Hamiltonian cycles in a directed graph. The basic idea of the method is sequential acceptance/rejection, which is successfully used in approximating the number of perfect matchings…

Data Structures and Algorithms · Computer Science 2009-11-23 Jinshan Zhang

An \textit{\(m \times n\) grid graph} is the induced subgraph of the square lattice whose vertex set consists of all integer grid points \(\{(i,j) : 0 \leq i < m,\ 0 \leq j < n\}\). Let $H$ and $K$ be Hamiltonian cycles in an $m \times n$…

Combinatorics · Mathematics 2026-01-13 Albi Kazazi

In 1999, Jacobson and Lehel conjectured that for $k \geq 3$, every $k$-regular Hamiltonian graph has cycles of at least linearly many different lengths. This was further strengthened by Verstra\"{e}te, who asked whether the regularity can…

Combinatorics · Mathematics 2021-04-16 Matija Bucić , Lior Gishboliner , Benny Sudakov