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Related papers: Cycle lengths in randomly perturbed graphs

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We study Hamiltonicity and pancyclicity in the graph obtained as the union of a deterministic $n$-vertex graph $H$ with $\delta(H)\geq\alpha n$ and a random $d$-regular graph $G$, for $d\in\{1,2\}$. When $G$ is a random $2$-regular graph,…

Combinatorics · Mathematics 2022-09-29 Alberto Espuny Díaz , António Girão

A graph G on n vertices is Hamiltonian if it contains a cycle of length n and pancyclic if it contains cycles of length $\ell$ for all $3 \le \ell \le n$. Write $\alpha(G)$ for the independence number of $G$, i.e. the size of the largest…

Combinatorics · Mathematics 2009-03-27 Peter Keevash , Benny Sudakov

In the model of randomly perturbed graphs we consider the union of a deterministic graph $\mathcal{G}_\alpha$ with minimum degree $\alpha n$ and the binomial random graph $\mathbb{G}(n,p)$. This model was introduced by Bohman, Frieze, and…

Combinatorics · Mathematics 2020-04-10 Max Hahn-Klimroth , Giulia S. Maesaka , Yannick Mogge , Samuel Mohr , Olaf Parczyk

Given a graph $G$ and an $r$-edge-colouring $\chi$ on $E(G)$, a Hamilton cycle $H\subset G$ is said to have $t$ colour-bias if $H$ contains $n/r+t$ edges of the same colour in $\chi$. Freschi, Hyde, Lada and Treglown showed every…

Combinatorics · Mathematics 2025-06-05 Wenchong Chen , Xinbu Cheng , Zhifei Yan

A well-known result due to Chvat\'al and Erd\H{o}s (1972) asserts that, if a graph $G$ satisfies $\kappa(G) \ge \alpha(G)$, where $\kappa(G)$ is the vertex-connectivity of $G$, then $G$ has a Hamilton cycle. We prove a similar result…

Combinatorics · Mathematics 2023-09-25 Shoham Letzter

In the standard random graph process, edges are added to an initially empty graph one by one uniformly at random. A classic result by Ajtai, Koml\'os, and Szemer\'edi, and independently by Bollob\'as, states that in the standard random…

Combinatorics · Mathematics 2026-03-24 Seonghyuk Im , Minseo Kim

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

In this paper we consider the existence of Hamilton cycles in the random graph $G=G_{n,m}^{\delta\geq 3}$. This a random graph chosen uniformly from the set of graphs with vertex set $[n]$, $m$ edges and minimum degree at least 3. Our…

Combinatorics · Mathematics 2020-06-23 Michael Anastos , Alan Frieze

We study Hamiltonicity in the union of an $n$-vertex graph $H$ with high minimum degree and a binomial random graph on the same vertex set. In particular, we consider the case when $H$ has minimum degree close to $n/2$. We determine the…

Combinatorics · Mathematics 2024-10-21 Alberto Espuny Díaz , Richarlotte Valérà Razafindravola

Finding general conditions which ensure that a graph is Hamiltonian is a central topic in graph theory. An old and well known conjecture in the area states that any $d$-regular $n$-vertex graph $G$ whose second largest eigenvalue in…

Combinatorics · Mathematics 2023-03-10 Stefan Glock , David Munhá Correia , Benny Sudakov

A classical result of Koml\'os, S\'ark\"ozy and Szemer\'edi states that every $n$-vertex graph with minimum degree at least $(1/2+ o(1))n$ contains every $n$-vertex tree with maximum degree $O(n/\log{n})$ as a subgraph, and the bounds on…

Combinatorics · Mathematics 2018-03-14 Felix Joos , Jaehoon Kim

In the past two decades, various properties of randomly perturbed/augmented (hyper)graphs have been intensively studied, since the model was introduced by Bohman, Frieze and Martin in 2003. The model usually considers a deterministic graph…

Combinatorics · Mathematics 2025-08-26 Jie Han , Seonghyuk Im , Bin Wang , Junxue Zhang

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

An $n$-vertex graph is Hamiltonian if it contains a cycle that covers all of its vertices and it is pancyclic if it contains cycles of all lengths from $3$ up to $n$. A celebrated meta-conjecture of Bondy states that every non-trivial…

Combinatorics · Mathematics 2023-01-25 Nemanja Draganić , David Munhá Correia , Benny Sudakov

We study Hamiltonicity in graphs obtained as the union of a deterministic $n$-vertex graph $H$ with linear degrees and a $d$-dimensional random geometric graph $G^d(n,r)$, for any $d\geq1$. We obtain an asymptotically optimal bound on the…

Combinatorics · Mathematics 2022-09-29 Alberto Espuny Díaz

We prove that for integers $2 \leq \ell < k$ and a small constant $c$, if a $k$-uniform hypergraph with linear minimum codegree is randomly `perturbed' by changing non-edges to edges independently at random with probability $p \geq…

Combinatorics · Mathematics 2018-02-13 Andrew McDowell , Richard Mycroft

Extremal properties of sparse graphs, randomly perturbed by the binomial random graph are considered. It is known that every $n$-vertex graph $G$ contains a complete minor of order $\Omega(n/\alpha(G))$. We prove that adding $\xi n$ random…

Combinatorics · Mathematics 2022-12-15 Elad Aigner-Horev , Dan Hefetz , Michael Krivelevich

Given an $n$-vertex graph $G$ with minimum degree at least $d n$ for some fixed $d > 0$, the distribution $G \cup \mathbb{G}(n,p)$ over the supergraphs of $G$ is referred to as a (random) {\sl perturbation} of $G$. We consider the…

Combinatorics · Mathematics 2020-04-21 Elad Aigner-Horev , Dan Hefetz

An $n$-vertex graph is called pancyclic if it contains a cycle of length $t$ for all $3 \leq t \leq n$. In this paper, we study pancyclicity of random graphs in the context of resilience, and prove that if $p \gg n^{-1/2}$, then the random…

Combinatorics · Mathematics 2015-03-17 Choongbum Lee , Wojciech Samotij

A seminal result by Koml\'os, Sark\"ozy, and Szemer\'edi states that if a graph $G$ with $n$ vertices has minimum degree at least $kn/(k + 1)$, for some $k \in \mathbb{N}$ and $n$ sufficiently large, then it contains the $k$-th power of a…

Combinatorics · Mathematics 2021-08-12 Rajko Nenadov , Miloš Trujić
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