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Related papers: A robust Corr\'adi--Hajnal Theorem

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Let $k \geq 2$ be an integer. Kouider and Lonc proved that the vertex set of every graph $G$ with $n \geq n_0(k)$ vertices and minimum degree at least $n/k$ can be covered by $k - 1$ cycles. Our main result states that for every $\alpha >…

Combinatorics · Mathematics 2021-11-18 Frank Mousset , Nemanja Škorić , Miloš Trujić

We prove that for each $D\ge 2$ there exists $c>0$ such that whenever $b\le c\big(\tfrac{n}{\log n}\big)^{1/D}$, in the $(1:b)$ Maker-Breaker game played on $E(K_n)$, Maker has a strategy to guarantee claiming a graph $G$ containing copies…

Combinatorics · Mathematics 2017-11-16 Peter Allen , Julia Böttcher , Yoshiharu Kohayakawa , Humberto Naves , Yury Person

Let $\R$ be the set of all finite graphs $G$ with the Ramsey property that every coloring of the edges of $G$ by two colors yields a monochromatic triangle. In this paper we establish a sharp threshold for random graphs with this property.…

Combinatorics · Mathematics 2007-05-23 Ehud Friedgut , Vojtech Rodl , Andrzej Rucinski , Prasad Tetali

We say that a (di)graph $G$ has a perfect $H$-packing if there exists a set of vertex-disjoint copies of $H$ which cover all the vertices in $G$. The seminal Hajnal--Szemer\'edi theorem characterises the minimum degree that ensures a graph…

Combinatorics · Mathematics 2015-01-27 Andrew Treglown

The celebrated Hajnal-Szemer\'edi theorem gives the precise minimum degree threshold that forces a graph to contain a perfect K_k-packing. Fischer's conjecture states that the analogous result holds for all multipartite graphs except for…

Combinatorics · Mathematics 2015-09-15 Peter Keevash , Richard Mycroft

In the random graph $G(n,p)$ with $pn$ bounded, the degrees of the vertices are almost i.i.d Poisson random variables with mean $\gl:= p(n-1)$. Motivated by this fact, we introduce the Poisson cloning model $G_{PC} (n,p)$ for random graphs…

Combinatorics · Mathematics 2008-05-28 Jeong Han Kim

Erd\H{o}s posed the problem of finding conditions on a graph $G$ that imply the largest number of edges in a triangle-free subgraph is equal to the largest number of edges in a bipartite subgraph. We generalize this problem to general…

Combinatorics · Mathematics 2021-02-03 Bingchen Qian , Chengfei Xie , Gennian Ge

We show that if the second eigenvalue $\lambda$ of a $d$-regular graph $G$ on $n \in 3 \mathbb{Z}$ vertices is at most $\varepsilon d^2/(n \log n)$, for a small constant $\varepsilon > 0$, then $G$ contains a triangle-factor. The bound on…

Combinatorics · Mathematics 2019-02-27 Rajko Nenadov

Let G be a graph with n vertices, and let k be an integer dividing n. G is said to be strongly k-colorable if for every partition of V(G) into disjoint sets V_1 \cup ... \cup V_r, all of size exactly k, there exists a proper vertex…

Combinatorics · Mathematics 2007-06-15 Po-Shen Loh , Benny Sudakov

In this paper, we are concerned with sufficient conditions for the existence of a $\{P_{2},P_{2k+1}\}$-factor. We prove that for $k\geq 3$, there exists $\varepsilon_{k}>0$ such that if a graph $G$ satisfies $\sum_{0\leq j\leq…

Combinatorics · Mathematics 2017-05-25 Yoshimi Egawa , Michitaka Furuya , Kenta Ozeki

We consider a number $\nu_n$ of components in a random graph $G(n,p)$ with $n$ vertices, where the probability of an edge is equal to $p$. By operating with special generating functions we shows the next asymptotic relation for factorial…

Probability · Mathematics 2019-04-03 Nikolay Kazimirow

The degree sequence of a graph is the sequence of the degrees of its vertices. If $\pi$ is a degree sequence of a graph $G$, then $G$ is a realization of $\pi$ and $G$ realizes $\pi$. Determining when a sequence of positive integers is…

Combinatorics · Mathematics 2022-11-28 Jiyun Guo , Miao Fu , Yuqin Zhang , Haiyan Li

A fractional matching of a graph $G$ is a function $f:E(G)\rightarrow [0, 1]$ such that for any $v\in V(G)$, $\sum_{e\in E_{G}(v)}f(e)\leq1$, where $E_{G}(v)=\{e\in E(G): e~ \mbox{is incident with} ~v~\mbox{in}~G\}$.The fractional matching…

Combinatorics · Mathematics 2023-04-25 Jing Lou , Ruifang Liu , Guoyan Ao

We say that a graph $G$ has a perfect $H$-packing if there exists a set of vertex-disjoint copies of $H$ which cover all the vertices in $G$. The seminal Hajnal--Szemer\'edi theorem characterises the minimum degree that ensures a graph $G$…

Combinatorics · Mathematics 2016-01-25 Andrew Treglown

An $n$-vertex graph $G$ of edge density $p$ is considered to be quasirandom if it shares several important properties with the random graph $G(n,p)$. A well-known theorem of Chung, Graham and Wilson states that many such `typical'…

Combinatorics · Mathematics 2020-06-17 E. Aigner-Horev , D. Conlon , H. Hàn , Y. Person , M. Schacht

For a graph $G=(V,E)$, let $bc(G)$ denote the minimum number of pairwise edge disjoint complete bipartite subgraphs of $G$ so that each edge of $G$ belongs to exactly one of them. It is easy to see that for every graph $G$, $bc(G) \leq n…

Combinatorics · Mathematics 2014-09-23 Noga Alon , Tom Bohman , Hao Huang

The celebrated Corr\'{a}di--Hajnal Theorem~\cite{CH63} and the Hajnal--Szemer\'{e}di Theorem~\cite{HS70} determined the exact minimum degree thresholds for a graph on $n$ vertices to contain $k$ vertex-disjoint copies of $K_r$, for $r=3$…

Combinatorics · Mathematics 2025-01-03 Jianfeng Hou , Caiyun Hu , Xizhi Liu , Yixiao Zhang

We consider the quantity $P(G)$ associated with a graph $G$ that is defined as the probability that a randomly chosen subtree of $G$ is spanning. Motivated by conjectures due to Chin, Gordon, MacPhee and Vincent on the behaviour of this…

Combinatorics · Mathematics 2019-10-17 Stephan Wagner

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

We find conditions for the connectivity of inhomogeneous random graphs with intermediate density. Our results generalize the classical result for G(n, p), when p = c log n/n. We draw n independent points X_i from a general distribution on a…

Probability · Mathematics 2012-10-25 Luc Devroye , Nicolas Fraiman
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