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Related papers: A note on spanning $K_r$-cycles in random graphs

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Let $G$ be a graph obtained as the union of some $n$-vertex graph $H_n$ with minimum degree $\delta(H_n)\geq\alpha n$ and a $d$-dimensional random geometric graph $G^d(n,r)$. We investigate under which conditions for $r$ the graph $G$ will…

Combinatorics · Mathematics 2023-01-18 Alberto Espuny Díaz , Joseph Hyde

For a given finite graph $G$ of minimum degree at least $k$, let $G_{p}$ be a random subgraph of $G$ obtained by taking each edge independently with probability $p$. We prove that (i) if $p \ge \omega/k$ for a function $\omega=\omega(k)$…

Combinatorics · Mathematics 2013-05-28 Michael Krivelevich , Choongbum Lee , Benny Sudakov

For each $\Delta>0$, we prove that there exists some $C=C(\Delta)$ for which the binomial random graph $G(n,C\log n/n)$ almost surely contains a copy of every tree with $n$ vertices and maximum degree at most $\Delta$. In doing so, we…

Combinatorics · Mathematics 2019-08-22 Richard Montgomery

Given a symmetric $n\times n$ matrix $P$ with $0 \le P(u, v)\le 1$, we define a random graph $G_{n, P}$ on $[n]$ by independently including any edge $\{u, v\}$ with probability $P(u, v)$. For $k\ge 1$ let $\mathcal{A}_k$ be the property of…

Combinatorics · Mathematics 2020-12-23 Tony Johansson

We prove that for every integer $k$, there exists $\varepsilon > 0$ such that for every n-vertex graph $G$ with no pivot-minor isomorphic to $C_k$, there exist disjoint sets $A,B \subseteq V(G)$ such that $|A|,|B| \geq \varepsilon n$, and…

Combinatorics · Mathematics 2021-07-02 Jaehoon Kim , Sang-il Oum

Let $H_1,\dots,H_k$ be Hamilton cycles in $K_n$, chosen independently and uniformly at random. We show, for $k = o(n^{1/100})$, that the probability of $H_1,\dots,H_k$ being edge-disjoint is $(1+o(1))e^{-2\binom{k}{2}}$. This extends a…

Combinatorics · Mathematics 2020-01-07 Asaf Ferber , Kaarel Haenni , Vishesh Jain

A classic result of Erd\H{o}s and P\'osa says that any graph contains either $k$ vertex-disjoint cycles or can be made acyclic by deleting at most $O(k \log k)$ vertices. Here we generalize this result by showing that for all numbers $k$…

Combinatorics · Mathematics 2016-03-25 Frank Mousset , Andreas Noever , Nemanja Škorić , Felix Weissenberger

We solve the conjecture posed by Fill, Scheinerman and Singer-Cohen and show the equivalence of the sharp threshold functions of the random intersection graph G(n,m,p) with $m >= n^3$ and a graph in which each edge appears independently.…

Combinatorics · Mathematics 2015-01-13 Katarzyna Rybarczyk

A graph is called Dirac if its minimum degree is at least half of the number of vertices in it. Joos and Kim showed that every collection $\mathbb{G}=\{G_1,\ldots,G_n\}$ of Dirac graphs on the same vertex set $V$ of size $n$ contains a…

Combinatorics · Mathematics 2026-04-14 Michael Anastos , Debsoumya Chakraborti

Let $\mathcal{G}(n,r,s)$ denote a uniformly random $r$-regular $s$-uniform hypergraph on $n$ vertices, where $s$ is a fixed constant and $r=r(n)$ may grow with $n$. An $\ell$-overlapping Hamilton cycle is a Hamilton cycle in which…

Combinatorics · Mathematics 2019-11-04 Daniel Altman , Catherine Greenhill , Mikhail Isaev , Reshma Ramadurai

Let $G$ be a graph of radius $r$ and diameter $d$ with $d\leq 2r-2$. We show that $G$ contains a cycle of length at least $4r-2d$, i.e. for its circumference it holds $c(G)\geq 4r-2d$. Moreover, for all positive integers $r$ and $d$ with…

Combinatorics · Mathematics 2012-07-03 Pavel Hrnčiar

Let $K_n^{(k)}$ be the complete $k$-graph on $n$ vertices. A $k$-uniform tight cycle is a $k$-graph with its vertices cyclically ordered so that every $k$ consecutive vertices form an edge and any two consecutive edges share exactly $k-1$…

Combinatorics · Mathematics 2025-02-18 Debmalya Bandyopadhyay , Allan Lo

Understanding how the cycles of a graph or digraph behave in general has always been an important point of graph theory. In this paper, we study the question of finding a set of $k$ vertex-disjoint cycles (resp. directed cycles) of distinct…

Combinatorics · Mathematics 2016-01-11 Julien Bensmail , Ararat Harutyunyan , Ngoc Khang Le , Binlong Li , Nicolas Lichiardopol

Let $EG_r(n,k)$ denote the maximum number of edges in an $n$-vertex $r$-uniform hypergraph with no Berge cycles of length $k$ or longer. In the first part of this work, we have found exact values of $EG_r(n,k)$ and described the structure…

Combinatorics · Mathematics 2018-07-18 Zoltan Furedi , Alexandr Kostochka , Ruth Luo

The celebrated canonical Ramsey theorem of Erd\H{o}s and Rado implies that for a given $k$-uniform hypergraph (or $k$-graph) $H$, if $n$ is sufficiently large then any colouring of the edges of the complete $k$-graph $K^{(k)}_n$ gives rise…

Combinatorics · Mathematics 2026-02-10 José D. Alvarado , Yoshiharu Kohayakawa , Patrick Morris , Guilherme O. Mota

Let $G$ be a simple graph with $n\geq4$ vertices and $d(x)+d(y)\geq n+k$ for each edge $xy\in E(G)$. In this work we prove that $G$ either contains a spanning closed trail containing any given edge set $X$ if $|X|\leq k$, or $G$ is a well…

Combinatorics · Mathematics 2017-06-23 Weihua Yang , Hong-jian Lai , Baoyindureng Wu

Given a bridgeless graph G, the well-known cycle double cover conjecture posits that there is a list of cycles of G, such that every edge appears in exactly two cycles. In this paper, we prove the cycle double cover conjecture. More…

Combinatorics · Mathematics 2018-11-22 A. Alipour , A. Tayebi

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

The threshold $p_c(H)$ for the event that the binomial random graph $G_{n,p}$ contains a copy of a graph $H$ is the unique $p$ for which $\mathbb{P}(H \subseteq G_{n,p}) = 1/2$, and the fractional expectation threshold $q_f(H)$ is roughly…

Combinatorics · Mathematics 2026-02-03 Quentin Dubroff

Order the vertices of a directed random graph \math{v_1,...,v_n}; edge \math{(v_i,v_j)} for \math{i<j} exists independently with probability \math{p}. This random graph model is related to certain spreading processes on networks. We…

Combinatorics · Mathematics 2012-09-12 Paul Horn , Malik Magdon-Ismail