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In previous papers, threshold probabilities for the properties of a random distance graph to contain strictly balanced graphs were found. We extend this result to arbitrary graphs and prove that the number of copies of a strictly balanced…

Combinatorics · Mathematics 2018-05-09 A. V. Burkin , M. E. Zhukovskii

A perfect $K_r$-tiling in a graph $G$ is a collection of vertex-disjoint copies of the graph $K_r$ in $G$ that covers all vertices of $G$. In this paper, we prove that the threshold for the existence of a perfect $K_{r}$-tiling of a…

Combinatorics · Mathematics 2025-04-11 Enrique Gomez-Leos , Ryan R. Martin

Let $H$ be a fixed graph on $v$ vertices. For an $n$-vertex graph $G$ with $n$ divisible by $v$, an $H$-{\em factor} of $G$ is a collection of $n/v$ copies of $H$ whose vertex sets partition $V(G)$. In this paper we consider the threshold…

Combinatorics · Mathematics 2008-03-25 A. Johansson , J. Kahn , V. Vu

We study the spectrum of a random multigraph with a degree sequence ${\bf D}_n=(D_i)_{i=1}^n$ and average degree $1 \ll \omega_n \ll n$, generated by the configuration model, and also the spectrum of the analogous random simple graph. We…

Probability · Mathematics 2020-05-15 Amir Dembo , Eyal Lubetzky , Yumeng Zhang

We proved that for every sufficiently large $n$, the complete graph $K_{2n}$ with an arbitrary edge signing $\sigma: E(K_{2n}) \to \{-1, +1\}$ admits a high discrepancy $1$-factor decomposition. That is, there exists a universal constant $c…

Combinatorics · Mathematics 2025-03-24 Jiangdong Ai , Fankang He , Seonghyuk Im , Hyunwoo Lee

We prove that the empirical spectral distribution of a (d_L, d_R)-biregular, bipartite random graph, under certain conditions, converges to a symmetrization of the Mar\v{c}enko-Pastur distribution of random matrix theory. This convergence…

Probability · Mathematics 2016-01-22 Ioana Dumitriu , Tobias Johnson

For all integers $n \geq k > d \geq 1$, let $m_{d}(k,n)$ be the minimum integer $D \geq 0$ such that every $k$-uniform $n$-vertex hypergraph $\mathcal H$ with minimum $d$-degree $\delta_{d}(\mathcal H)$ at least $D$ has an optimal matching.…

Combinatorics · Mathematics 2024-04-17 Dong Yeap Kang , Tom Kelly , Daniela Kühn , Deryk Osthus , Vincent Pfenninger

We show that each perfect matching in a bipartite graph $G$ intersects at least half of the perfect matchings in $G$. This result has equivalent formulations in terms of the permanent of the adjacency matrix of a graph, and in terms of…

Combinatorics · Mathematics 2019-10-14 Matija Bucic , Pat Devlin , Mo Hendon , Dru Horne , Ben Lund

Let $\mathbf{A}$ be an $n\times n$-matrix over $\mathbb{F}_2$ whose every entry equals $1$ with probability $d/n$ independently for a fixed $d>0$. Draw a vector $\mathbf{y}$ randomly from the column space of $\mathbf{A}$. It is a simple…

Combinatorics · Mathematics 2023-09-08 Amin Coja-Oghlan , Oliver Cooley , Mihyun Kang , Joon Lee , Jean Bernoulli Ravelomanana

In this note we study inhomogeneous random bipartite graphs in random environment. These graphs can be thought of as an extension of the classical Erd\"os-R\'enyi random graphs in a random environment. We show that the expected number of…

Combinatorics · Mathematics 2016-11-29 Jairo Bochi , Godofredo Iommi , Mario Ponce

We present the first algorithm for generating random variates exactly uniformly from the set of perfect matchings of a bipartite graph with a polynomial expected running time over a nontrivial set of graphs. Previous Markov chain approaches…

Probability · Mathematics 2007-05-23 Mark Huber

The K{\L}R conjecture of Kohayakawa, {\L}uczak, and R\"odl is a statement that allows one to prove that asymptotically almost surely all subgraphs of the random graph G_{n,p}, for sufficiently large p : = p(n), satisfy an embedding lemma…

Combinatorics · Mathematics 2016-02-22 D. Conlon , W. T. Gowers , W. Samotij , M. Schacht

A perfect $K_t$-matching in a graph $G$ is a spanning subgraph consisting of vertex disjoint copies of $K_t$. A classic theorem of Hajnal and Szemer\'edi states that if $G$ is a graph of order $n$ with minimum degree $\delta(G) \ge…

Combinatorics · Mathematics 2013-01-01 Allan Lo , Klas Markström

Let k >= 2 and F be a linear k-uniform hypergraph with v vertices. We prove that if n is sufficiently large and v|n, then every quasirandom k-uniform hypergraph on n vertices with constant edge density and minimum degree $\Omega(n^{k-1})$…

Combinatorics · Mathematics 2014-02-18 John Lenz , Dhruv Mubayi

We describe two constructions of (very) dense graphs which are edge disjoint unions of large {\em induced} matchings. The first construction exhibits graphs on $N$ vertices with ${N \choose 2}-o(N^2)$ edges, which can be decomposed into…

Combinatorics · Mathematics 2011-11-09 Noga Alon , Ankur Moitra , Benny Sudakov

Let $X_{2k}$ be a set of $2k$ labeled points in convex position in the plane. We consider geometric non-intersecting straight-line perfect matchings of $X_{2k}$. Two such matchings, $M$ and $M'$, are disjoint compatible if they do not have…

Combinatorics · Mathematics 2014-03-24 Oswin Aichholzer , Andrei Asinowski , Tillmann Miltzow

In this work we establish several monotonicity and decomposition results in the framework of random regular graphs. Among other results, we show that, for a wide range of parameters $d_1 \leq d_2$, there exists a coupling of $G(n,d_1)$ and…

Combinatorics · Mathematics 2025-05-30 Lawrence Hollom , Lyuben Lichev , Adva Mond , Julien Portier , Yiting Wang

We present a new approach to showing that random graphs are nearly optimal expanders. This approach is based on recent deep results in combinatorial group theory. It applies to both regular and irregular random graphs. Let G be a random…

Combinatorics · Mathematics 2015-08-24 Doron Puder

In 2000, Cohn, Kenyon and Propp studied uniformly random perfect matchings of large induced subgraphs of $\mathbb Z^2$ (a.k.a. dimer configurations or domino tilings) and developed a large deviation theory for the associated height…

Probability · Mathematics 2026-05-08 Nishant Chandgotia , Scott Sheffield , Catherine Wolfram

In this paper we extend a classical theorem of Corr\'adi and Hajnal into the setting of sparse random graphs. We show that if $p(n) \gg (\log n / n)^{1/2}$, then asymptotically almost surely every subgraph of $G(n,p)$ with minimum degree at…

Combinatorics · Mathematics 2011-11-02 József Balogh , Choongbum Lee , Wojciech Samotij