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Related papers: The Hamilton cycle space of random graphs

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We show for an arbitrary $\ell_p$ norm that the property that a random geometric graph $\mathcal G(n,r)$ contains a Hamiltonian cycle exhibits a sharp threshold at $r=r(n)=\sqrt{\frac{\log n}{\alpha_p n}}$, where $\alpha_p$ is the area of…

Discrete Mathematics · Computer Science 2007-05-23 J. Diaz , D. Mitsche , X. Perez

Let $\mu(G)$ denote the minimum number of edges whose addition to $G$ results in a Hamiltonian graph, and let $\hat{\mu}(G)$ denote the minimum number of edges whose addition to $G$ results in a pancyclic graph. We study the distributions…

Combinatorics · Mathematics 2025-01-23 Yahav Alon , Michael Anastos

We use a randomised embedding method to prove that for all \alpha>0 any sufficiently large oriented graph G with minimum in-degree and out-degree \delta^+(G),\delta^-(G)\geq (3/8+\alpha)|G| contains every possible orientation of a Hamilton…

Combinatorics · Mathematics 2009-08-06 Luke Kelly

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

We establish an inclusion relation between two uniform models of random $k$-graphs (for constant $k \ge 2$) on $n$ labeled vertices: $\mathbb G^{(k)}(n,m)$, the random $k$-graph with $m$ edges, and $\mathbb R^{(k)}(n,d)$, the random…

Combinatorics · Mathematics 2019-11-12 Andrzej Dudek , Alan Frieze , Andrzej Ruciński , Matas Šileikis

We show that if pn >> log n, the binomial random graph G_{n,p} has an approximate Hamilton decomposition. More precisely, we show that in this range G_{n,p} contains a set of edge-disjoint Hamilton cycles covering almost all of its edges.…

Combinatorics · Mathematics 2013-07-05 Fiachra Knox , Daniela Kühn , Deryk Osthus

Let $G$ be a graph on $n\geq 3$ vertices, claw the bipartite graph $K_{1,3}$, and $Z_i$ the graph obtained from a triangle by attaching a path of length $i$ to its one vertex. $G$ is called 1-heavy if at least one end vertex of each induced…

Combinatorics · Mathematics 2013-01-07 Bo Ning , Bing Chen , Shenggui Zhang

A Hamiltonian path (cycle) in a graph is a path (cycle, respectively) which passes through all of its vertices. The problems of deciding the existence of a Hamiltonian cycle (path) in an input graph are well known to be NP-complete, and…

Combinatorics · Mathematics 2024-03-07 Nikola Jedličková , Jan Kratochvíl

A graph $G$ is said to be $\mathcal H(n,\Delta)$-universal if it contains every graph on $n$ vertices with maximum degree at most $\Delta$. It is known that for any $\varepsilon > 0$ and any natural number $\Delta$ there exists $c > 0$ such…

Combinatorics · Mathematics 2016-02-02 David Conlon , Asaf Ferber , Rajko Nenadov , Nemanja Škorić

Let G (V, E) be a simple graph with vertex set V and edge set E. A generalized cycle is a subgraph such that any vertex degree is even. A simple cycle (briefly in a cycle) is a connected subgraph such that every vertex has degree 2. A basis…

Discrete Mathematics · Computer Science 2016-11-23 Heping Jiang

A graph on n vertices is called pancyclic if it contains a cycle of length l for all 3 \le l \le n. In 1972, Erdos proved that if G is a Hamiltonian graph on n > 4k^4 vertices with independence number k, then G is pancyclic. He then…

Combinatorics · Mathematics 2011-11-09 Choongbum Lee , Benny Sudakov

Resolving a conjecture of K\"uhn and Osthus from 2012, we show that $p= 1/\sqrt{n}$ is the threshold for the random graph $G_{n,p}$ to contain the square of a Hamilton cycle.

Combinatorics · Mathematics 2020-10-20 Jeff Kahn , Bhargav Narayanan , Jinyoung Park

It is a longstanding conjecture that every simple drawing of a complete graph on $n \geq 3$ vertices contains a crossing-free Hamiltonian cycle. We strengthen this conjecture to "there exists a crossing-free Hamiltonian path between each…

Combinatorics · Mathematics 2024-03-05 Oswin Aichholzer , Joachim Orthaber , Birgit Vogtenhuber

Let $\mathcal{H}$ be a given finite (possibly empty) family of connected graphs, each containing a cycle, and let $G$ be an arbitrary finite $\mathcal{H}$-free graph with minimum degree at least $k$. For $p \in [0,1]$, we form a $p$-random…

Combinatorics · Mathematics 2014-01-17 Michael Krivelevich , Wojciech Samotij

A loose Hamilton cycle in a hypergraph is a cyclic sequence of edges covering all vertices in which only every two consecutive edges intersect and do so in exactly one vertex. With Dirac's theorem in mind, it is natural to ask what minimum…

Combinatorics · Mathematics 2024-04-29 Kalina Petrova , Miloš Trujić

Let $H$ be an edge colored hypergraph. We say that $H$ contains a \emph{rainbow} copy of a hypergraph $S$ if it contains an isomorphic copy of $S$ with all edges of distinct colors. We consider the following setting. A randomly edge colored…

Combinatorics · Mathematics 2015-06-10 Asaf Ferber , Michael Krivelevich

We design a randomized algorithm that finds a Hamilton cycle in $\mathcal{O}(n)$ time with high probability in a random graph $G_{n,p}$ with edge probability $p\ge C \log n / n$. This closes a gap left open in a seminal paper by Angluin and…

Data Structures and Algorithms · Computer Science 2020-12-07 Rajko Nenadov , Angelika Steger , Pascal Su

We investigate the existence of a rainbow Hamilton cycle in a uniformly edge-coloured randomly perturbed digraph. We show that for every $\delta \in (0,1)$ there exists $C = C(\delta) > 0$ such that the following holds. Let $D_0$ be an…

Combinatorics · Mathematics 2024-11-20 Kyriakos Katsamaktsis , Shoham Letzter , Amedeo Sgueglia

The bipartite independence number of a graph $G$, denoted as $\tilde\alpha(G)$, is the minimal number $k$ such that there exist positive integers $a$ and $b$ with $a+b=k+1$ with the property that for any two sets $A,B\subseteq V(G)$ with…

Combinatorics · Mathematics 2023-02-27 Nemanja Draganić , David Munhá Correia , Benny Sudakov

We determine the sharp threshold for Hamilton cycles in randomly perturbed sparse graphs. For any $\alpha=\alpha(n)=o(1)$, let $G_{\alpha}$ be an $n$-vertex graph with minimum degree $\delta(G_{\alpha})\ge\alpha n$. We prove that if…

Combinatorics · Mathematics 2026-05-29 Guorui Ma , Zhifei Yan